21573952 has 56 divisors (see below), whose sum is σ = 46085760. Its totient is φ = 9984000.

The previous prime is 21573907. The next prime is 21573971. The reversal of 21573952 is 25937512.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85827 + ... + 86077.

It is an arithmetic number, because the mean of its divisors is an integer number (822960).

Almost surely, 2^21573952 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 21573952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23042880).

21573952 is an abundant number, since it is smaller than the sum of its proper divisors (24511808).

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

21573952 is a wasteful number, since it uses less digits than its factorization.

21573952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 349 counting only the distinct ones).

The product of its digits is 18900, while the sum is 34.

The square root of 21573952 is about 4644.7768514752. The cubic root of 21573952 is about 278.3833367399.

The spelling of 21573952 in words is "twenty-one million, five hundred seventy-three thousand, nine hundred fifty-two".