561 (number)
561 is the natural number following 560 and followed by 562.
Template:Numbers 0-1000 | |
Cardinal | five hundred sixty-one |
Ordinal | 561st |
Factorization | |
Roman numeral | DLXI |
Binary | 1000110001 |
Hexadecimal | 231 |
In mathematics
561 is the smallest Carmichael number.