20787757477956 has 96 divisors (see below), whose sum is σ = 63258040858880. Its totient is φ = 5778836047872.

The previous prime is 20787757477901. The next prime is 20787757477957. The reversal of 20787757477956 is 65977475778702.

20787757477956 is a `hidden beast` number, since 2 + 0 + 7 + 8 + 7 + 7 + 57 + 477 + 95 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (20787757477957) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 371553565 + ... + 371609508.

Almost surely, 2^{20787757477956} is an apocalyptic number.

It is an amenable number.

20787757477956 is an abundant number, since it is smaller than the sum of its proper divisors (42470283380924).

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

20787757477956 is a wasteful number, since it uses less digits than its factorization.

20787757477956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743163130 (or 743163122 counting only the distinct ones).

The product of its (nonzero) digits is 10164873600, while the sum is 81.

The spelling of 20787757477956 in words is "twenty trillion, seven hundred eighty-seven billion, seven hundred fifty-seven million, four hundred seventy-seven thousand, nine hundred fifty-six".