21332313 has 36 divisors (see below), whose sum is σ = 33448740. Its totient is φ = 13075776.

The previous prime is 21332261. The next prime is 21332329. The reversal of 21332313 is 31323312.

21332313 is a `hidden beast` number, since 21 + 332 + 313 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15586704 + 5745609 = 3948^2 + 2397^2 .

It is not a de Polignac number, because 21332313 - 2⁸ = 21332057 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21332393) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 453856 + ... + 453902.

Almost surely, 2^21332313 is an apocalyptic number.

It is an amenable number.

21332313 is a deficient number, since it is larger than the sum of its proper divisors (12116427).

21332313 is a wasteful number, since it uses less digits than its factorization.

21332313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 116 counting only the distinct ones).

The product of its digits is 324, while the sum is 18.

The square root of 21332313 is about 4618.6916978729. The cubic root of 21332313 is about 277.3400880471.

Adding to 21332313 its reverse (31323312), we get a palindrome (52655625).

Subtracting 21332313 from its reverse (31323312), we obtain a palindrome (9990999).

The spelling of 21332313 in words is "twenty-one million, three hundred thirty-two thousand, three hundred thirteen".