21511314520 has 32 divisors (see below), whose sum is σ = 48466018800. Its totient is φ = 8592870528.

The previous prime is 21511314511. The next prime is 21511314551. The reversal of 21511314520 is 2541311512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 334299 + ... + 393418.

Almost surely, 2^21511314520 is an apocalyptic number.

21511314520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21511314520 is an abundant number, since it is smaller than the sum of its proper divisors (26954704280).

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

21511314520 is a wasteful number, since it uses less digits than its factorization.

21511314520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728467 (or 728463 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

The spelling of 21511314520 in words is "twenty-one billion, five hundred eleven million, three hundred fourteen thousand, five hundred twenty".