21972160 has 112 divisors (see below), whose sum is σ = 63422784. Its totient is φ = 7077888.

The previous prime is 21972127. The next prime is 21972173. The reversal of 21972160 is 6127912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 37792 + ... + 38368.

Almost surely, 2^21972160 is an apocalyptic number.

21972160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21972160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31711392).

21972160 is an abundant number, since it is smaller than the sum of its proper divisors (41450624).

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

21972160 is a wasteful number, since it uses less digits than its factorization.

21972160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 21972160 is about 4687.4470663678. The cubic root of 21972160 is about 280.0856880600.

The spelling of 21972160 in words is "twenty-one million, nine hundred seventy-two thousand, one hundred sixty".