21672099 has 6 divisors (see below), whose sum is σ = 31304156. Its totient is φ = 14448060.

The previous prime is 21672097. The next prime is 21672107. The reversal of 21672099 is 99027612.

It is not a de Polignac number, because 21672099 - 2¹ = 21672097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21672097) 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 5 ways as a sum of consecutive naturals, for example, 1203997 + ... + 1204014.

Almost surely, 2^21672099 is an apocalyptic number.

21672099 is a deficient number, since it is larger than the sum of its proper divisors (9632057).

21672099 is a wasteful number, since it uses less digits than its factorization.

21672099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2408017 (or 2408014 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 21672099 is about 4655.3301708901. The cubic root of 21672099 is about 278.8048506217.

The spelling of 21672099 in words is "twenty-one million, six hundred seventy-two thousand, ninety-nine".