21547968 has 112 divisors (see below), whose sum is σ = 62727840. Its totient is φ = 6488064.

The previous prime is 21547951. The next prime is 21547973. The reversal of 21547968 is 86974512.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 222096 + ... + 222192.

It is an arithmetic number, because the mean of its divisors is an integer number (560070).

Almost surely, 2^21547968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21547968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31363920).

21547968 is an abundant number, since it is smaller than the sum of its proper divisors (41179872).

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

21547968 is a wasteful number, since it uses less digits than its factorization.

21547968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 204 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 21547968 is about 4641.9788883622. The cubic root of 21547968 is about 278.2715287810.

The spelling of 21547968 in words is "twenty-one million, five hundred forty-seven thousand, nine hundred sixty-eight".