138125978 has 4 divisors (see below), whose sum is σ = 207188970. Its totient is φ = 69062988.

The previous prime is 138125951. The next prime is 138125983. The reversal of 138125978 is 879521831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 70442449 + 67683529 = 8393^2 + 8227^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34531493 + ... + 34531496.

Almost surely, 2^138125978 is an apocalyptic number.

138125978 is a deficient number, since it is larger than the sum of its proper divisors (69062992).

138125978 is an equidigital number, since it uses as much as digits as its factorization.

138125978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69062991.

The product of its digits is 120960, while the sum is 44.

The square root of 138125978 is about 11752.7008810741. The cubic root of 138125978 is about 516.9221262313.

The spelling of 138125978 in words is "one hundred thirty-eight million, one hundred twenty-five thousand, nine hundred seventy-eight".