55561599081 has 16 divisors (see below), whose sum is σ = 82367305920. Its totient is φ = 37016844480.

The previous prime is 55561599059. The next prime is 55561599089. The reversal of 55561599081 is 18099516555.

55561599081 is a `hidden beast` number, since 5 + 556 + 1 + 5 + 9 + 9 + 0 + 81 = 666.

It is not a de Polignac number, because 55561599081 - 2¹⁸ = 55561336937 is a prime.

It is a super-2 number, since 2×55561599081² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55561599089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 630720 + ... + 713393.

It is an arithmetic number, because the mean of its divisors is an integer number (5147956620).

Almost surely, 2^55561599081 is an apocalyptic number.

It is an amenable number.

55561599081 is a deficient number, since it is larger than the sum of its proper divisors (26805706839).

55561599081 is a wasteful number, since it uses less digits than its factorization.

55561599081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1345653 (or 1345647 counting only the distinct ones).

The product of its (nonzero) digits is 2430000, while the sum is 54.

The spelling of 55561599081 in words is "fifty-five billion, five hundred sixty-one million, five hundred ninety-nine thousand, eighty-one".