21131012 has 24 divisors (see below), whose sum is σ = 43163904. Its totient is φ = 8862912.

The previous prime is 21131009. The next prime is 21131029. The reversal of 21131012 is 21013112.

It is a junction number, because it is equal to n+sod(n) for n = 21130984 and 21131002.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6713 + ... + 9344.

It is an arithmetic number, because the mean of its divisors is an integer number (1798496).

Almost surely, 2^21131012 is an apocalyptic number.

It is an amenable number.

21131012 is an abundant number, since it is smaller than the sum of its proper divisors (22032892).

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

21131012 is a wasteful number, since it uses less digits than its factorization.

21131012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16115 (or 16113 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21131012 is about 4596.8480505668. The cubic root of 21131012 is about 276.4649622551.

Adding to 21131012 its reverse (21013112), we get a palindrome (42144124).

It can be divided in two parts, 2113 and 1012, that added together give a 5-th power (3125 = 5⁵).

The spelling of 21131012 in words is "twenty-one million, one hundred thirty-one thousand, twelve".