21579480 has 256 divisors, whose sum is σ = 81648000. Its totient is φ = 5031936.

The previous prime is 21579479. The next prime is 21579491. The reversal of 21579480 is 8497512.

21579480 is a `hidden beast` number, since 2 + 1 + 579 + 4 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 407134 + ... + 407186.

Almost surely, 2^21579480 is an apocalyptic number.

21579480 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 21579480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40824000).

21579480 is an abundant number, since it is smaller than the sum of its proper divisors (60068520).

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

21579480 is a wasteful number, since it uses less digits than its factorization.

21579480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21579480 is about 4645.3718903872. The cubic root of 21579480 is about 278.4071118873.

The spelling of 21579480 in words is "twenty-one million, five hundred seventy-nine thousand, four hundred eighty".