561611556605 has 32 divisors (see below), whose sum is σ = 762671635200. Its totient is φ = 393261568000.

The previous prime is 561611556599. The next prime is 561611556631. The reversal of 561611556605 is 506655116165.

It is not a de Polignac number, because 561611556605 - 2²⁶ = 561544447741 is a prime.

It is a super-2 number, since 2×561611556605² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 561611556605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82205 + ... + 1063005.

It is an arithmetic number, because the mean of its divisors is an integer number (23833488600).

Almost surely, 2^561611556605 is an apocalyptic number.

561611556605 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

561611556605 is a deficient number, since it is larger than the sum of its proper divisors (201060078595).

561611556605 is a wasteful number, since it uses less digits than its factorization.

561611556605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 981205.

The product of its (nonzero) digits is 810000, while the sum is 47.

The spelling of 561611556605 in words is "five hundred sixty-one billion, six hundred eleven million, five hundred fifty-six thousand, six hundred five".