138399079 has 24 divisors (see below), whose sum is σ = 174551328. Its totient is φ = 108763200.

The previous prime is 138399077. The next prime is 138399083. The reversal of 138399079 is 970993831.

It is not a de Polignac number, because 138399079 - 2¹ = 138399077 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138399071) 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 in 23 ways as a sum of consecutive naturals, for example, 105729 + ... + 107029.

It is an arithmetic number, because the mean of its divisors is an integer number (7272972).

Almost surely, 2^138399079 is an apocalyptic number.

138399079 is a deficient number, since it is larger than the sum of its proper divisors (36152249).

138399079 is a wasteful number, since it uses less digits than its factorization.

138399079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1495 (or 1488 counting only the distinct ones).

The product of its (nonzero) digits is 367416, while the sum is 49.

The square root of 138399079 is about 11764.3137921427. The cubic root of 138399079 is about 517.2625859878.

The spelling of 138399079 in words is "one hundred thirty-eight million, three hundred ninety-nine thousand, seventy-nine".