138355979 has 8 divisors (see below), whose sum is σ = 146703168. Its totient is φ = 130032000.

The previous prime is 138355963. The next prime is 138355981. The reversal of 138355979 is 979553831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138355979 - 2⁴ = 138355963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138355079) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 7349 + ... + 18185.

It is an arithmetic number, because the mean of its divisors is an integer number (18337896).

Almost surely, 2^138355979 is an apocalyptic number.

138355979 is a deficient number, since it is larger than the sum of its proper divisors (8347189).

138355979 is a wasteful number, since it uses less digits than its factorization.

138355979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11605.

The product of its digits is 1020600, while the sum is 50.

The square root of 138355979 is about 11762.4818384557. The cubic root of 138355979 is about 517.2088854086.

The spelling of 138355979 in words is "one hundred thirty-eight million, three hundred fifty-five thousand, nine hundred seventy-nine".