21588120 has 96 divisors (see below), whose sum is σ = 72792720. Its totient is φ = 5754240.

The previous prime is 21588103. The next prime is 21588139. The reversal of 21588120 is 2188512.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 9.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8610 + ... + 10830.

Almost surely, 2^21588120 is an apocalyptic number.

21588120 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 21588120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36396360).

21588120 is an abundant number, since it is smaller than the sum of its proper divisors (51204600).

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

21588120 is a wasteful number, since it uses less digits than its factorization.

21588120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2247 (or 2231 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 21588120 is about 4646.3017551597. The cubic root of 21588120 is about 278.4442631762. Note that the first 3 decimals are identical.

The spelling of 21588120 in words is "twenty-one million, five hundred eighty-eight thousand, one hundred twenty".