202123138 has 24 divisors (see below), whose sum is σ = 353303100. Its totient is φ = 86472288.

The previous prime is 202123111. The next prime is 202123139. The reversal of 202123138 is 831321202.

It can be written as a sum of positive squares in 2 ways, for example, as 202123089 + 49 = 14217^2 + 7^2 .

It is not an unprimeable number, because it can be changed into a prime (202123139) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68028 + ... + 70936.

Almost surely, 2^202123138 is an apocalyptic number.

202123138 is a deficient number, since it is larger than the sum of its proper divisors (151179962).

202123138 is a wasteful number, since it uses less digits than its factorization.

202123138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3634 (or 3627 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 202123138 is about 14217.0017232889. The cubic root of 202123138 is about 586.8656323389.

The spelling of 202123138 in words is "two hundred two million, one hundred twenty-three thousand, one hundred thirty-eight".