21183872 has 32 divisors (see below), whose sum is σ = 42411600. Its totient is φ = 10539520.

The previous prime is 21183863. The next prime is 21183889. The reversal of 21183872 is 27838112.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45722 + ... + 46182.

Almost surely, 2^21183872 is an apocalyptic number.

It is an amenable number.

21183872 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

21183872 is an equidigital number, since it uses as much as digits as its factorization.

21183872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834 (or 822 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 21183872 is about 4602.5940511846. The cubic root of 21183872 is about 276.6952993705.

The spelling of 21183872 in words is "twenty-one million, one hundred eighty-three thousand, eight hundred seventy-two".