21512311320 has 64 divisors (see below), whose sum is σ = 66111020640. Its totient is φ = 5596697600.

The previous prime is 21512311319. The next prime is 21512311321. The reversal of 21512311320 is 2311321512.

It is an interprime number because it is at equal distance from previous prime (21512311319) and next prime (21512311321).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512311321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2181291 + ... + 2191130.

Almost surely, 2^21512311320 is an apocalyptic number.

21512311320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21512311320 is an abundant number, since it is smaller than the sum of its proper divisors (44598709320).

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

21512311320 is a wasteful number, since it uses less digits than its factorization.

21512311320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4372476 (or 4372472 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 21512311320 its reverse (2311321512), we get a palindrome (23823632832).

The spelling of 21512311320 in words is "twenty-one billion, five hundred twelve million, three hundred eleven thousand, three hundred twenty".