21231331320 has 64 divisors (see below), whose sum is σ = 63762020640. Its totient is φ = 5655641600.

The previous prime is 21231331283. The next prime is 21231331337. The reversal of 21231331320 is 2313313212.

It is a super-2 number, since 2×21231331320² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18910 + ... + 206930.

Almost surely, 2^21231331320 is an apocalyptic number.

21231331320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231331320 is an abundant number, since it is smaller than the sum of its proper divisors (42530689320).

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

21231331320 is a wasteful number, since it uses less digits than its factorization.

21231331320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188976 (or 188972 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21231331320 its reverse (2313313212), we get a palindrome (23544644532).

The spelling of 21231331320 in words is "twenty-one billion, two hundred thirty-one million, three hundred thirty-one thousand, three hundred twenty".