21050538 has 16 divisors (see below), whose sum is σ = 42495840. Its totient is φ = 6951056.

The previous prime is 21050527. The next prime is 21050567. The reversal of 21050538 is 83505012.

It is a Curzon number.

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, 15753 + ... + 17036.

It is an arithmetic number, because the mean of its divisors is an integer number (2655990).

Almost surely, 2^21050538 is an apocalyptic number.

21050538 is an abundant number, since it is smaller than the sum of its proper divisors (21445302).

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

21050538 is a wasteful number, since it uses less digits than its factorization.

21050538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32901.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21050538 is about 4588.0865292625. The cubic root of 21050538 is about 276.1135586056.

The spelling of 21050538 in words is "twenty-one million, fifty thousand, five hundred thirty-eight".