21594172 has 6 divisors (see below), whose sum is σ = 37789808. Its totient is φ = 10797084.

The previous prime is 21594169. The next prime is 21594179. The reversal of 21594172 is 27149512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21594179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2699268 + ... + 2699275.

Almost surely, 2^21594172 is an apocalyptic number.

It is an amenable number.

21594172 is a deficient number, since it is larger than the sum of its proper divisors (16195636).

21594172 is a wasteful number, since it uses less digits than its factorization.

21594172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5398547 (or 5398545 counting only the distinct ones).

The product of its digits is 5040, while the sum is 31.

The square root of 21594172 is about 4646.9529801796. The cubic root of 21594172 is about 278.4702803751.

The spelling of 21594172 in words is "twenty-one million, five hundred ninety-four thousand, one hundred seventy-two".