21431012 has 24 divisors (see below), whose sum is σ = 39631200. Its totient is φ = 10112256.

The previous prime is 21430991. The next prime is 21431017. The reversal of 21431012 is 21013412.

It is not an unprimeable number, because it can be changed into a prime (21431017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31508 + ... + 32180.

It is an arithmetic number, because the mean of its divisors is an integer number (1651300).

Almost surely, 2^21431012 is an apocalyptic number.

It is an amenable number.

21431012 is a deficient number, since it is larger than the sum of its proper divisors (18200188).

21431012 is a wasteful number, since it uses less digits than its factorization.

21431012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115 (or 1113 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21431012 is about 4629.3641032004. The cubic root of 21431012 is about 277.7671566191.

Adding to 21431012 its reverse (21013412), we get a palindrome (42444424).

The spelling of 21431012 in words is "twenty-one million, four hundred thirty-one thousand, twelve".