21672959 has 16 divisors (see below), whose sum is σ = 27430656. Its totient is φ = 16632000.

The previous prime is 21672913. The next prime is 21672967. The reversal of 21672959 is 95927612.

It is not a de Polignac number, because 21672959 - 2²⁴ = 4895743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21672979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3059 + ... + 7259.

It is an arithmetic number, because the mean of its divisors is an integer number (1714416).

Almost surely, 2^21672959 is an apocalyptic number.

21672959 is a deficient number, since it is larger than the sum of its proper divisors (5757697).

21672959 is a wasteful number, since it uses less digits than its factorization.

21672959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4286.

The product of its digits is 68040, while the sum is 41.

The square root of 21672959 is about 4655.4225372140. The cubic root of 21672959 is about 278.8085384509.

The spelling of 21672959 in words is "twenty-one million, six hundred seventy-two thousand, nine hundred fifty-nine".