21580480 has 56 divisors (see below), whose sum is σ = 54425088. Its totient is φ = 8122368.

The previous prime is 21580477. The next prime is 21580501. The reversal of 21580480 is 8408512.

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, 3457 + ... + 7423.

Almost surely, 2^21580480 is an apocalyptic number.

21580480 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 21580480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27212544).

21580480 is an abundant number, since it is smaller than the sum of its proper divisors (32844608).

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

21580480 is a wasteful number, since it uses less digits than its factorization.

21580480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4001 (or 3991 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 21580480 is about 4645.4795231494. The cubic root of 21580480 is about 278.4114123124.

Adding to 21580480 its reverse (8408512), we get a palindrome (29988992).

The spelling of 21580480 in words is "twenty-one million, five hundred eighty thousand, four hundred eighty".