20643632 has 20 divisors (see below), whose sum is σ = 41079216. Its totient is φ = 10042560.

The previous prime is 20643611. The next prime is 20643641. The reversal of 20643632 is 23634602.

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, 16844 + ... + 18027.

Almost surely, 2^20643632 is an apocalyptic number.

It is an amenable number.

20643632 is a deficient number, since it is larger than the sum of its proper divisors (20435584).

20643632 is a wasteful number, since it uses less digits than its factorization.

20643632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34916 (or 34910 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 26.

The square root of 20643632 is about 4543.5263837684. The cubic root of 20643632 is about 274.3228829012.

The spelling of 20643632 in words is "twenty million, six hundred forty-three thousand, six hundred thirty-two".