21748572 has 36 divisors (see below), whose sum is σ = 55165656. Its totient is φ = 7224480.

The previous prime is 21748561. The next prime is 21748589. The reversal of 21748572 is 27584712.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11622 + ... + 13362.

Almost surely, 2^21748572 is an apocalyptic number.

It is an amenable number.

21748572 is an abundant number, since it is smaller than the sum of its proper divisors (33417084).

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

21748572 is a wasteful number, since it uses less digits than its factorization.

21748572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2098 (or 2093 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 21748572 is about 4663.5364263614. The cubic root of 21748572 is about 279.1323994869.

The spelling of 21748572 in words is "twenty-one million, seven hundred forty-eight thousand, five hundred seventy-two".