21332480 has 80 divisors (see below), whose sum is σ = 55168344. Its totient is φ = 7864320.

The previous prime is 21332471. The next prime is 21332503. The reversal of 21332480 is 8423312.

It can be written as a sum of positive squares in 4 ways, for example, as 17707264 + 3625216 = 4208^2 + 1904^2 .

It is a tau number, because it is divible by the number of its divisors (80).

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, 32960 + ... + 33600.

Almost surely, 2^21332480 is an apocalyptic number.

21332480 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 21332480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27584172).

21332480 is an abundant number, since it is smaller than the sum of its proper divisors (33835864).

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

21332480 is an equidigital number, since it uses as much as digits as its factorization.

21332480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21332480 is about 4618.7097765502. The cubic root of 21332480 is about 277.3408117642.

Adding to 21332480 its reverse (8423312), we get a palindrome (29755792).

It can be divided in two parts, 21332 and 480, that added together give a palindrome (21812).

The spelling of 21332480 in words is "twenty-one million, three hundred thirty-two thousand, four hundred eighty".