138649959 has 18 divisors (see below), whose sum is σ = 232970400. Its totient is φ = 79228296.

The previous prime is 138649939. The next prime is 138649963. The reversal of 138649959 is 959946831.

It is not a de Polignac number, because 138649959 - 2⁷ = 138649831 is a prime.

It is a super-2 number, since 2×138649959² = 38447622261403362, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138649939) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 156759 + ... + 157640.

It is an arithmetic number, because the mean of its divisors is an integer number (12942800).

Almost surely, 2^138649959 is an apocalyptic number.

138649959 is a deficient number, since it is larger than the sum of its proper divisors (94320441).

138649959 is a wasteful number, since it uses less digits than its factorization.

138649959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314419 (or 314409 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 54.

The square root of 138649959 is about 11774.9717197113. The cubic root of 138649959 is about 517.5749495870.

The spelling of 138649959 in words is "one hundred thirty-eight million, six hundred forty-nine thousand, nine hundred fifty-nine".