21139712 has 36 divisors (see below), whose sum is σ = 46039056. Its totient is φ = 9607680.

The previous prime is 21139711. The next prime is 21139717. The reversal of 21139712 is 21793112.

It is not an unprimeable number, because it can be changed into a prime (21139711) 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, 938 + ... + 6569.

Almost surely, 2^21139712 is an apocalyptic number.

21139712 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21139712 is an abundant number, since it is smaller than the sum of its proper divisors (24899344).

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

21139712 is an equidigital number, since it uses as much as digits as its factorization.

21139712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7534 (or 7520 counting only the distinct ones).

The product of its digits is 756, while the sum is 26.

The square root of 21139712 is about 4597.7942537700. The cubic root of 21139712 is about 276.5028988379.

The spelling of 21139712 in words is "twenty-one million, one hundred thirty-nine thousand, seven hundred twelve".