21577393756 has 12 divisors (see below), whose sum is σ = 37761550960. Its totient is φ = 10788379200.

The previous prime is 21577393639. The next prime is 21577393771. The reversal of 21577393756 is 65739377512.

It is a junction number, because it is equal to n+sod(n) for n = 21577393697 and 21577393706.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141985 + ... + 251623.

Almost surely, 2^21577393756 is an apocalyptic number.

It is an amenable number.

21577393756 is a deficient number, since it is larger than the sum of its proper divisors (16184157204).

21577393756 is a wasteful number, since it uses less digits than its factorization.

21577393756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158844 (or 158842 counting only the distinct ones).

The product of its digits is 8334900, while the sum is 55.

The spelling of 21577393756 in words is "twenty-one billion, five hundred seventy-seven million, three hundred ninety-three thousand, seven hundred fifty-six".