138665799 has 12 divisors (see below), whose sum is σ = 200580016. Its totient is φ = 92312352.

The previous prime is 138665797. The next prime is 138665831. The reversal of 138665799 is 997566831.

138665799 is a `hidden beast` number, since 1 + 3 + 8 + 66 + 579 + 9 = 666.

It is not a de Polignac number, because 138665799 - 2¹ = 138665797 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 (138665797) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4054 + ... + 17139.

Almost surely, 2^138665799 is an apocalyptic number.

138665799 is a deficient number, since it is larger than the sum of its proper divisors (61914217).

138665799 is a wasteful number, since it uses less digits than its factorization.

138665799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21926 (or 21923 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 54.

The square root of 138665799 is about 11775.6443135822. The cubic root of 138665799 is about 517.5946588728.

The spelling of 138665799 in words is "one hundred thirty-eight million, six hundred sixty-five thousand, seven hundred ninety-nine".