21642432 has 56 divisors (see below), whose sum is σ = 65446656. Its totient is φ = 6183168.

The previous prime is 21642421. The next prime is 21642437. The reversal of 21642432 is 23424612.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-3 number, since 3×21642432³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21642437) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6708 + ... + 9395.

Almost surely, 2^21642432 is an apocalyptic number.

It is an amenable number.

21642432 is an abundant number, since it is smaller than the sum of its proper divisors (43804224).

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

21642432 is a wasteful number, since it uses less digits than its factorization.

21642432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16125 (or 16115 counting only the distinct ones).

The product of its digits is 2304, while the sum is 24.

The square root of 21642432 is about 4652.1427321182. The cubic root of 21642432 is about 278.6775736010.

The spelling of 21642432 in words is "twenty-one million, six hundred forty-two thousand, four hundred thirty-two".