21874637 has 8 divisors (see below), whose sum is σ = 22365720. Its totient is φ = 21386560.

The previous prime is 21874627. The next prime is 21874673. The reversal of 21874637 is 73647812.

It can be written as a sum of positive squares in 4 ways, for example, as 4116841 + 17757796 = 2029^2 + 4214^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21874637 - 2⁴ = 21874621 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21874637.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21874627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20087 + ... + 21147.

It is an arithmetic number, because the mean of its divisors is an integer number (2795715).

Almost surely, 2^21874637 is an apocalyptic number.

It is an amenable number.

21874637 is a deficient number, since it is larger than the sum of its proper divisors (491083).

21874637 is a wasteful number, since it uses less digits than its factorization.

21874637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503.

The product of its digits is 56448, while the sum is 38.

The square root of 21874637 is about 4677.0329269741. The cubic root of 21874637 is about 279.6706885248.

The spelling of 21874637 in words is "twenty-one million, eight hundred seventy-four thousand, six hundred thirty-seven".