21038508 has 48 divisors (see below), whose sum is σ = 55224960. Its totient is φ = 6925392.

The previous prime is 21038483. The next prime is 21038519. The reversal of 21038508 is 80583012.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7791 + ... + 10137.

It is an arithmetic number, because the mean of its divisors is an integer number (1150520).

Almost surely, 2^21038508 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21038508, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27612480).

21038508 is an abundant number, since it is smaller than the sum of its proper divisors (34186452).

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

21038508 is a wasteful number, since it uses less digits than its factorization.

21038508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2443 (or 2435 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21038508 is about 4586.7753378599. The cubic root of 21038508 is about 276.0609506221.

The spelling of 21038508 in words is "twenty-one million, thirty-eight thousand, five hundred eight".