21432960 has 144 divisors (see below), whose sum is σ = 75243870. Its totient is φ = 5621760.

The previous prime is 21432949. The next prime is 21432967. The reversal of 21432960 is 6923412.

It can be written as a sum of positive squares in 3 ways, for example, as 4981824 + 16451136 = 2232^2 + 4056^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (21432967) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 351330 + ... + 351390.

Almost surely, 2^21432960 is an apocalyptic number.

21432960 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 21432960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37621935).

21432960 is an abundant number, since it is smaller than the sum of its proper divisors (53810910).

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

21432960 is an equidigital number, since it uses as much as digits as its factorization.

21432960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21432960 is about 4629.5744944865. The cubic root of 21432960 is about 277.7755723677.

The spelling of 21432960 in words is "twenty-one million, four hundred thirty-two thousand, nine hundred sixty".