20887756477 has 8 divisors (see below), whose sum is σ = 24139944000. Its totient is φ = 17702624544.

The previous prime is 20887756471. The next prime is 20887756517. The reversal of 20887756477 is 77465778802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20887756477 - 2³¹ = 18740272829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20887756471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16763227 + ... + 16764472.

It is an arithmetic number, because the mean of its divisors is an integer number (3017493000).

Almost surely, 2^20887756477 is an apocalyptic number.

It is an amenable number.

20887756477 is a deficient number, since it is larger than the sum of its proper divisors (3252187523).

20887756477 is an equidigital number, since it uses as much as digits as its factorization.

20887756477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33527795.

The product of its (nonzero) digits is 36879360, while the sum is 61.

The spelling of 20887756477 in words is "twenty billion, eight hundred eighty-seven million, seven hundred fifty-six thousand, four hundred seventy-seven".