21183172 has 12 divisors (see below), whose sum is σ = 37105936. Its totient is φ = 10581480.

The previous prime is 21183167. The next prime is 21183209. The reversal of 21183172 is 27138112.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4147 + ... + 7717.

Almost surely, 2^21183172 is an apocalyptic number.

It is an amenable number.

21183172 is a deficient number, since it is larger than the sum of its proper divisors (15922764).

21183172 is a wasteful number, since it uses less digits than its factorization.

21183172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5058 (or 5056 counting only the distinct ones).

The product of its digits is 672, while the sum is 25.

The square root of 21183172 is about 4602.5180064830. The cubic root of 21183172 is about 276.6922516298.

The spelling of 21183172 in words is "twenty-one million, one hundred eighty-three thousand, one hundred seventy-two".