2138978872 has 16 divisors (see below), whose sum is σ = 4011323400. Its totient is φ = 1069292640.

The previous prime is 2138978869. The next prime is 2138978893. The reversal of 2138978872 is 2788798312.

It is a super-2 number, since 2×2138978872² = 9150461229724784768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28279 + ... + 71257.

Almost surely, 2^2138978872 is an apocalyptic number.

It is an amenable number.

2138978872 is a deficient number, since it is larger than the sum of its proper divisors (1872344528).

2138978872 is a wasteful number, since it uses less digits than its factorization.

2138978872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49206 (or 49202 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 55.

The square root of 2138978872 is about 46249.0959046769. The cubic root of 2138978872 is about 1288.4537433401.

The spelling of 2138978872 in words is "two billion, one hundred thirty-eight million, nine hundred seventy-eight thousand, eight hundred seventy-two".