56661224978 has 18 divisors (see below), whose sum is σ = 90294566463. Its totient is φ = 26661412800.

The previous prime is 56661224941. The next prime is 56661225007. The reversal of 56661224978 is 87942216665.

It can be written as a sum of positive squares in 5 ways, for example, as 56160942289 + 500282689 = 236983^2 + 22367^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=168317.

It is a super-2 number, since 2×56661224978² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5717828 + ... + 5727728.

Almost surely, 2^56661224978 is an apocalyptic number.

56661224978 is a deficient number, since it is larger than the sum of its proper divisors (33633341485).

56661224978 is an frugal number, since it uses more digits than its factorization.

56661224978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19838 (or 9920 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 56.

The spelling of 56661224978 in words is "fifty-six billion, six hundred sixty-one million, two hundred twenty-four thousand, nine hundred seventy-eight".