20951871885 has 112 divisors (see below), whose sum is σ = 44472683520. Its totient is φ = 9268680960.

The previous prime is 20951871851. The next prime is 20951871887. The reversal of 20951871885 is 58817815902.

It is not a de Polignac number, because 20951871885 - 2⁷ = 20951871757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20951871887) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 777721 + ... + 804209.

Almost surely, 2^20951871885 is an apocalyptic number.

It is an amenable number.

20951871885 is an abundant number, since it is smaller than the sum of its proper divisors (23520811635).

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

20951871885 is an equidigital number, since it uses as much as digits as its factorization.

20951871885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26550 (or 26535 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 54.

The spelling of 20951871885 in words is "twenty billion, nine hundred fifty-one million, eight hundred seventy-one thousand, eight hundred eighty-five".