20787757477564 has 48 divisors (see below), whose sum is σ = 45447480481536. Its totient is φ = 8082631065600.

The previous prime is 20787757477537. The next prime is 20787757477573. The reversal of 20787757477564 is 46577475778702.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68578629 + ... + 68881084.

It is an arithmetic number, because the mean of its divisors is an integer number (946822510032).

Almost surely, 2^{20787757477564} is an apocalyptic number.

It is an amenable number.

20787757477564 is an abundant number, since it is smaller than the sum of its proper divisors (24659723003972).

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

20787757477564 is a wasteful number, since it uses less digits than its factorization.

20787757477564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137460226 (or 137460224 counting only the distinct ones).

The product of its (nonzero) digits is 4517721600, while the sum is 76.

The spelling of 20787757477564 in words is "twenty trillion, seven hundred eighty-seven billion, seven hundred fifty-seven million, four hundred seventy-seven thousand, five hundred sixty-four".