21945632 has 24 divisors (see below), whose sum is σ = 43311996. Its totient is φ = 10945792.

The previous prime is 21945601. The next prime is 21945641. The reversal of 21945632 is 23654912.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21939856 + 5776 = 4684^2 + 76^2 .

It is a super-2 number, since 2×21945632² = 963221527758848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

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, 21158 + ... + 22170.

Almost surely, 2^21945632 is an apocalyptic number.

It is an amenable number.

21945632 is a deficient number, since it is larger than the sum of its proper divisors (21366364).

21945632 is a wasteful number, since it uses less digits than its factorization.

21945632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1700 (or 1692 counting only the distinct ones).

The product of its digits is 12960, while the sum is 32.

The square root of 21945632 is about 4684.6165264619. The cubic root of 21945632 is about 279.9729225516.

The spelling of 21945632 in words is "twenty-one million, nine hundred forty-five thousand, six hundred thirty-two".