21050868 has 48 divisors (see below), whose sum is σ = 51226560. Its totient is φ = 6720000.

The previous prime is 21050857. The next prime is 21050873. The reversal of 21050868 is 86805012.

It is a congruent number.

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, 83743 + ... + 83993.

It is an arithmetic number, because the mean of its divisors is an integer number (1067220).

Almost surely, 2^21050868 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 21050868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25613280).

21050868 is an abundant number, since it is smaller than the sum of its proper divisors (30175692).

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

21050868 is a wasteful number, since it uses less digits than its factorization.

21050868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 526 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 21050868 is about 4588.1224918260. The cubic root of 21050868 is about 276.1150014349.

The spelling of 21050868 in words is "twenty-one million, fifty thousand, eight hundred sixty-eight".