21131332 has 6 divisors (see below), whose sum is σ = 36979838. Its totient is φ = 10565664.

The previous prime is 21131317. The next prime is 21131333. The reversal of 21131332 is 23313112.

It can be written as a sum of positive squares in only one way, i.e., 13645636 + 7485696 = 3694^2 + 2736^2 .

It is not an unprimeable number, because it can be changed into a prime (21131333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2641413 + ... + 2641420.

Almost surely, 2^21131332 is an apocalyptic number.

It is an amenable number.

21131332 is a deficient number, since it is larger than the sum of its proper divisors (15848506).

21131332 is a wasteful number, since it uses less digits than its factorization.

21131332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5282837 (or 5282835 counting only the distinct ones).

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

The square root of 21131332 is about 4596.8828568934. The cubic root of 21131332 is about 276.4663578081.

Adding to 21131332 its reverse (23313112), we get a palindrome (44444444).

The spelling of 21131332 in words is "twenty-one million, one hundred thirty-one thousand, three hundred thirty-two".