138778764 has 24 divisors (see below), whose sum is σ = 324083760. Its totient is φ = 46221504.

The previous prime is 138778763. The next prime is 138778777. The reversal of 138778764 is 467877831.

It is not an unprimeable number, because it can be changed into a prime (138778763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13102 + ... + 21194.

It is an arithmetic number, because the mean of its divisors is an integer number (13503490).

Almost surely, 2^138778764 is an apocalyptic number.

It is an amenable number.

138778764 is an abundant number, since it is smaller than the sum of its proper divisors (185304996).

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

138778764 is a wasteful number, since it uses less digits than its factorization.

138778764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9529 (or 9527 counting only the distinct ones).

The product of its digits is 1580544, while the sum is 51.

The square root of 138778764 is about 11780.4398899192. The cubic root of 138778764 is about 517.7351746803.

The spelling of 138778764 in words is "one hundred thirty-eight million, seven hundred seventy-eight thousand, seven hundred sixty-four".