56665523978 has 24 divisors (see below), whose sum is σ = 97484165856. Its totient is φ = 24199453080.

The previous prime is 56665523977. The next prime is 56665523983. The reversal of 56665523978 is 87932556665.

It is a self number, because there is not a number n which added to its sum of digits gives 56665523978.

It is not an unprimeable number, because it can be changed into a prime (56665523977) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15604223 + ... + 15607853.

It is an arithmetic number, because the mean of its divisors is an integer number (4061840244).

Almost surely, 2^56665523978 is an apocalyptic number.

56665523978 is a deficient number, since it is larger than the sum of its proper divisors (40818641878).

56665523978 is an frugal number, since it uses more digits than its factorization.

56665523978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7578 (or 3947 counting only the distinct ones).

The product of its digits is 81648000, while the sum is 62.

The spelling of 56665523978 in words is "fifty-six billion, six hundred sixty-five million, five hundred twenty-three thousand, nine hundred seventy-eight".