20864878520 has 16 divisors (see below), whose sum is σ = 46945976760. Its totient is φ = 8345951392.

The previous prime is 20864878511. The next prime is 20864878537. The reversal of 20864878520 is 2587846802.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260810942 + ... + 260811021.

Almost surely, 2^20864878520 is an apocalyptic number.

20864878520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20864878520 is an abundant number, since it is smaller than the sum of its proper divisors (26081098240).

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

20864878520 is a wasteful number, since it uses less digits than its factorization.

20864878520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521621974 (or 521621970 counting only the distinct ones).

The product of its (nonzero) digits is 1720320, while the sum is 50.

The spelling of 20864878520 in words is "twenty billion, eight hundred sixty-four million, eight hundred seventy-eight thousand, five hundred twenty".