21130508 has 24 divisors (see below), whose sum is σ = 44486400. Its totient is φ = 8579088.

The previous prime is 21130481. The next prime is 21130511. The reversal of 21130508 is 80503112.

It is a self number, because there is not a number n which added to its sum of digits gives 21130508.

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, 19328 + ... + 20391.

It is an arithmetic number, because the mean of its divisors is an integer number (1853600).

Almost surely, 2^21130508 is an apocalyptic number.

21130508 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21130508 is an abundant number, since it is smaller than the sum of its proper divisors (23355892).

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

21130508 is a wasteful number, since it uses less digits than its factorization.

21130508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39749 (or 39747 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 21130508 is about 4596.7932300681. The cubic root of 21130508 is about 276.4627642306.

The spelling of 21130508 in words is "twenty-one million, one hundred thirty thousand, five hundred eight".