20876887644921 has 320 divisors, whose sum is σ = 42015536640000. Its totient is φ = 10212342416640.

The previous prime is 20876887644917. The next prime is 20876887644937. The reversal of 20876887644921 is 12944678867802.

20876887644921 is a `hidden beast` number, since 2 + 0 + 8 + 7 + 68 + 8 + 76 + 4 + 492 + 1 = 666.

It is not a de Polignac number, because 20876887644921 - 2² = 20876887644917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20876887644921.

It is not an unprimeable number, because it can be changed into a prime (20876887644901) by changing a digit.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 969699285 + ... + 969720813.

It is an arithmetic number, because the mean of its divisors is an integer number (131298552000).

Almost surely, 2^{20876887644921} is an apocalyptic number.

20876887644921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20876887644921 is an abundant number, since it is smaller than the sum of its proper divisors (21138648995079).

20876887644921 is a wasteful number, since it uses less digits than its factorization.

20876887644921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21759 (or 21736 counting only the distinct ones).

The product of its (nonzero) digits is 520224768, while the sum is 72.

The spelling of 20876887644921 in words is "twenty trillion, eight hundred seventy-six billion, eight hundred eighty-seven million, six hundred forty-four thousand, nine hundred twenty-one".