21250138 has 32 divisors (see below), whose sum is σ = 39989376. Its totient is φ = 8244288.

The previous prime is 21250133. The next prime is 21250139. The reversal of 21250138 is 83105212.

It is not an unprimeable number, because it can be changed into a prime (21250133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8545 + ... + 10747.

It is an arithmetic number, because the mean of its divisors is an integer number (1249668).

Almost surely, 2^21250138 is an apocalyptic number.

21250138 is a deficient number, since it is larger than the sum of its proper divisors (18739238).

21250138 is a wasteful number, since it uses less digits than its factorization.

21250138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 21250138 is about 4609.7871968237. The cubic root of 21250138 is about 276.9835124230.

The spelling of 21250138 in words is "twenty-one million, two hundred fifty thousand, one hundred thirty-eight".