138778766388 has 72 divisors (see below), whose sum is σ = 354027605568. Its totient is φ = 45834501888.

The previous prime is 138778766377. The next prime is 138778766389. The reversal of 138778766388 is 883667877831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138778766389) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22871331 + ... + 22877397.

Almost surely, 2^138778766388 is an apocalyptic number.

138778766388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138778766388 is an abundant number, since it is smaller than the sum of its proper divisors (215248839180).

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

138778766388 is a wasteful number, since it uses less digits than its factorization.

138778766388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11813 (or 11808 counting only the distinct ones).

The product of its digits is 455196672, while the sum is 72.

The spelling of 138778766388 in words is "one hundred thirty-eight billion, seven hundred seventy-eight million, seven hundred sixty-six thousand, three hundred eighty-eight".