20787757477900 has 72 divisors (see below), whose sum is σ = 51569492223200. Its totient is φ = 7125039383040.

The previous prime is 20787757477871. The next prime is 20787757477901. The reversal of 20787757477900 is 977475778702.

It is a Harshad number since it is a multiple of its sum of digits (70).

It is a self number, because there is not a number n which added to its sum of digits gives 20787757477900.

It is not an unprimeable number, because it can be changed into a prime (20787757477901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2287425 + ... + 6841624.

Almost surely, 2^{20787757477900} is an apocalyptic number.

20787757477900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20787757477900 is an abundant number, since it is smaller than the sum of its proper divisors (30781734745300).

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

20787757477900 is a wasteful number, since it uses less digits than its factorization.

20787757477900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9132323 (or 9132316 counting only the distinct ones).

The product of its (nonzero) digits is 338829120, while the sum is 70.

The spelling of 20787757477900 in words is "twenty trillion, seven hundred eighty-seven billion, seven hundred fifty-seven million, four hundred seventy-seven thousand, nine hundred".