21672256 has 28 divisors (see below), whose sum is σ = 44878752. Its totient is φ = 10364288.

The previous prime is 21672239. The next prime is 21672271. The reversal of 21672256 is 65227612.

It is a congruent number.

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, 5890 + ... + 8833.

Almost surely, 2^21672256 is an apocalyptic number.

It is an amenable number.

21672256 is an abundant number, since it is smaller than the sum of its proper divisors (23206496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21672256 is a wasteful number, since it uses less digits than its factorization.

21672256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14758 (or 14748 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 21672256 is about 4655.3470332511. The cubic root of 21672256 is about 278.8055238722.

Adding to 21672256 its reverse (65227612), we get a palindrome (86899868).

The spelling of 21672256 in words is "twenty-one million, six hundred seventy-two thousand, two hundred fifty-six".