21672328 has 16 divisors (see below), whose sum is σ = 40711680. Its totient is φ = 10815888.

The previous prime is 21672323. The next prime is 21672337. The reversal of 21672328 is 82327612.

It is a self number, because there is not a number n which added to its sum of digits gives 21672328.

It is not an unprimeable number, because it can be changed into a prime (21672323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2625 + ... + 7087.

It is an arithmetic number, because the mean of its divisors is an integer number (2544480).

Almost surely, 2^21672328 is an apocalyptic number.

It is an amenable number.

21672328 is a deficient number, since it is larger than the sum of its proper divisors (19039352).

21672328 is a wasteful number, since it uses less digits than its factorization.

21672328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5076 (or 5072 counting only the distinct ones).

The product of its digits is 8064, while the sum is 31.

The square root of 21672328 is about 4655.3547662880. The cubic root of 21672328 is about 278.8058326229.

The spelling of 21672328 in words is "twenty-one million, six hundred seventy-two thousand, three hundred twenty-eight".