21672364 has 24 divisors (see below), whose sum is σ = 43575840. Its totient is φ = 9238656.

The previous prime is 21672359. The next prime is 21672373. The reversal of 21672364 is 46327612.

It is a super-2 number, since 2×21672364² = 939382722696992, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3552 + ... + 7480.

It is an arithmetic number, because the mean of its divisors is an integer number (1815660).

Almost surely, 2^21672364 is an apocalyptic number.

It is an amenable number.

21672364 is an abundant number, since it is smaller than the sum of its proper divisors (21903476).

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

21672364 is a wasteful number, since it uses less digits than its factorization.

21672364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4137 (or 4135 counting only the distinct ones).

The product of its digits is 12096, while the sum is 31.

The square root of 21672364 is about 4655.3586328016. The cubic root of 21672364 is about 278.8059869981.

Adding to 21672364 its reverse (46327612), we get a palindrome (67999976).

The spelling of 21672364 in words is "twenty-one million, six hundred seventy-two thousand, three hundred sixty-four".