21311332 has 12 divisors (see below), whose sum is σ = 42622720. Its totient is φ = 9133416.

The previous prime is 21311261. The next prime is 21311347. The reversal of 21311332 is 23311312.

21311332 is an admirable number.

It is a super-2 number, since 2×21311332² = 908345743228448, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 380532 + ... + 380587.

Almost surely, 2^21311332 is an apocalyptic number.

It is an amenable number.

21311332 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21311332 is a wasteful number, since it uses less digits than its factorization.

21311332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761130 (or 761128 counting only the distinct ones).

The product of its digits is 108, while the sum is 16.

The square root of 21311332 is about 4616.4198249293. The cubic root of 21311332 is about 277.2491339921.

Adding to 21311332 its reverse (23311312), we get a palindrome (44622644).

The spelling of 21311332 in words is "twenty-one million, three hundred eleven thousand, three hundred thirty-two".