21371748 has 24 divisors (see below), whose sum is σ = 50430240. Its totient is φ = 7043520.

The previous prime is 21371717. The next prime is 21371759. The reversal of 21371748 is 84717312.

It is a happy number.

It is a super-2 number, since 2×21371748² = 913503225151008, which contains 22 as substring.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 8938 + ... + 11073.

It is an arithmetic number, because the mean of its divisors is an integer number (2101260).

Almost surely, 2^21371748 is an apocalyptic number.

It is an amenable number.

21371748 is an abundant number, since it is smaller than the sum of its proper divisors (29058492).

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

21371748 is a wasteful number, since it uses less digits than its factorization.

21371748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20107 (or 20105 counting only the distinct ones).

The product of its digits is 9408, while the sum is 33.

The square root of 21371748 is about 4622.9587928079. The cubic root of 21371748 is about 277.5108801837.

The spelling of 21371748 in words is "twenty-one million, three hundred seventy-one thousand, seven hundred forty-eight".