21332961 has 12 divisors (see below), whose sum is σ = 33184788. Its totient is φ = 13127904.

The previous prime is 21332959. The next prime is 21332963. The reversal of 21332961 is 16923312.

It is an interprime number because it is at equal distance from previous prime (21332959) and next prime (21332963).

It can be written as a sum of positive squares in 2 ways, for example, as 14676561 + 6656400 = 3831^2 + 2580^2 .

It is not a de Polignac number, because 21332961 - 2¹ = 21332959 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21332963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 91050 + ... + 91283.

It is an arithmetic number, because the mean of its divisors is an integer number (2765399).

Almost surely, 2^21332961 is an apocalyptic number.

It is an amenable number.

21332961 is a deficient number, since it is larger than the sum of its proper divisors (11851827).

21332961 is a wasteful number, since it uses less digits than its factorization.

21332961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182352 (or 182349 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 21332961 is about 4618.7618470755. The cubic root of 21332961 is about 277.3428962214.

The spelling of 21332961 in words is "twenty-one million, three hundred thirty-two thousand, nine hundred sixty-one".