21233172 has 12 divisors (see below), whose sum is σ = 49544096. Its totient is φ = 7077720.

The previous prime is 21233161. The next prime is 21233183. The reversal of 21233172 is 27133212.

It is an interprime number because it is at equal distance from previous prime (21233161) and next prime (21233183).

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884704 + ... + 884727.

Almost surely, 2^21233172 is an apocalyptic number.

It is an amenable number.

21233172 is an abundant number, since it is smaller than the sum of its proper divisors (28310924).

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

21233172 is a wasteful number, since it uses less digits than its factorization.

21233172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769438 (or 1769436 counting only the distinct ones).

The product of its digits is 504, while the sum is 21.

The square root of 21233172 is about 4607.9466142741. The cubic root of 21233172 is about 276.9097787299.

Adding to 21233172 its reverse (27133212), we get a palindrome (48366384).

The spelling of 21233172 in words is "twenty-one million, two hundred thirty-three thousand, one hundred seventy-two".