21672004 has 12 divisors (see below), whose sum is σ = 37968364. Its totient is φ = 10823904.

The previous prime is 21671999. The next prime is 21672011. The reversal of 21672004 is 40027612.

It can be written as a sum of positive squares in 2 ways, for example, as 20232004 + 1440000 = 4498^2 + 1200^2 .

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, 1894 + ... + 6850.

Almost surely, 2^21672004 is an apocalyptic number.

It is an amenable number.

21672004 is a deficient number, since it is larger than the sum of its proper divisors (16296360).

21672004 is a wasteful number, since it uses less digits than its factorization.

21672004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6054 (or 6052 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 21672004 is about 4655.3199675210. The cubic root of 21672004 is about 278.8044432392.

Adding to 21672004 its reverse (40027612), we get a palindrome (61699616).

The spelling of 21672004 in words is "twenty-one million, six hundred seventy-two thousand, four".