138278776 has 8 divisors (see below), whose sum is σ = 259272720. Its totient is φ = 69139384.

The previous prime is 138278771. The next prime is 138278779. The reversal of 138278776 is 677872831.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138278771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8642416 + ... + 8642431.

It is an arithmetic number, because the mean of its divisors is an integer number (32409090).

Almost surely, 2^138278776 is an apocalyptic number.

It is an amenable number.

138278776 is a deficient number, since it is larger than the sum of its proper divisors (120993944).

138278776 is a wasteful number, since it uses less digits than its factorization.

138278776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17284853 (or 17284849 counting only the distinct ones).

The product of its digits is 790272, while the sum is 49.

The square root of 138278776 is about 11759.1996326281. The cubic root of 138278776 is about 517.1126662036.

The spelling of 138278776 in words is "one hundred thirty-eight million, two hundred seventy-eight thousand, seven hundred seventy-six".