21131301320 has 16 divisors (see below), whose sum is σ = 47545428060. Its totient is φ = 8452520512.

The previous prime is 21131301293. The next prime is 21131301329. The reversal of 21131301320 is 2310313112.

It can be written as a sum of positive squares in 2 ways, for example, as 21128948164 + 2353156 = 145358^2 + 1534^2 .

It is not an unprimeable number, because it can be changed into a prime (21131301329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264141227 + ... + 264141306.

Almost surely, 2^21131301320 is an apocalyptic number.

21131301320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131301320 is an abundant number, since it is smaller than the sum of its proper divisors (26414126740).

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

21131301320 is a wasteful number, since it uses less digits than its factorization.

21131301320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528282544 (or 528282540 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21131301320 its reverse (2310313112), we get a palindrome (23441614432).

The spelling of 21131301320 in words is "twenty-one billion, one hundred thirty-one million, three hundred one thousand, three hundred twenty".