138831777 has 12 divisors (see below), whose sum is σ = 229182720. Its totient is φ = 79332408.

The previous prime is 138831761. The next prime is 138831811. The reversal of 138831777 is 777138831.

It is not a de Polignac number, because 138831777 - 2⁴ = 138831761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138831977) 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, 1101777 + ... + 1101902.

It is an arithmetic number, because the mean of its divisors is an integer number (19098560).

Almost surely, 2^138831777 is an apocalyptic number.

It is an amenable number.

138831777 is a deficient number, since it is larger than the sum of its proper divisors (90350943).

138831777 is a wasteful number, since it uses less digits than its factorization.

138831777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2203692 (or 2203689 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The square root of 138831777 is about 11782.6897183962. The cubic root of 138831777 is about 517.8010906267.

The spelling of 138831777 in words is "one hundred thirty-eight million, eight hundred thirty-one thousand, seven hundred seventy-seven".