56787780666 has 64 divisors (see below), whose sum is σ = 121538672640. Its totient is φ = 17645960640.

The previous prime is 56787780653. The next prime is 56787780677. The reversal of 56787780666 is 66608778765.

It is a junction number, because it is equal to n+sod(n) for n = 56787780597 and 56787780606.

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, 2725195 + ... + 2745953.

It is an arithmetic number, because the mean of its divisors is an integer number (1899041760).

Almost surely, 2^56787780666 is an apocalyptic number.

56787780666 is an abundant number, since it is smaller than the sum of its proper divisors (64750891974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

56787780666 is a wasteful number, since it uses less digits than its factorization.

56787780666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21291.

The product of its (nonzero) digits is 142248960, while the sum is 66.

The spelling of 56787780666 in words is "fifty-six billion, seven hundred eighty-seven million, seven hundred eighty thousand, six hundred sixty-six".