138402679 has 4 divisors (see below), whose sum is σ = 139459320. Its totient is φ = 137346040.

The previous prime is 138402659. The next prime is 138402683. The reversal of 138402679 is 976204831.

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

It is a cyclic number.

It is not a de Polignac number, because 138402679 - 2⁵ = 138402647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138402629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 528124 + ... + 528385.

It is an arithmetic number, because the mean of its divisors is an integer number (34864830).

Almost surely, 2^138402679 is an apocalyptic number.

138402679 is a deficient number, since it is larger than the sum of its proper divisors (1056641).

138402679 is a wasteful number, since it uses less digits than its factorization.

138402679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056640.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 138402679 is about 11764.4667962471. The cubic root of 138402679 is about 517.2670709145.

The spelling of 138402679 in words is "one hundred thirty-eight million, four hundred two thousand, six hundred seventy-nine".