21537152 has 96 divisors (see below), whose sum is σ = 54064080. Its totient is φ = 8322048.

The previous prime is 21537151. The next prime is 21537161. The reversal of 21537152 is 25173512.

It is a super-2 number, since 2×21537152² = 927697832542208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 500843 + ... + 500885.

Almost surely, 2^21537152 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 21537152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27032040).

21537152 is an abundant number, since it is smaller than the sum of its proper divisors (32526928).

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

21537152 is an equidigital number, since it uses as much as digits as its factorization.

21537152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 65 counting only the distinct ones).

The product of its digits is 2100, while the sum is 26.

The square root of 21537152 is about 4640.8137217518. The cubic root of 21537152 is about 278.2249615349.

The spelling of 21537152 in words is "twenty-one million, five hundred thirty-seven thousand, one hundred fifty-two".