138691790 has 16 divisors (see below), whose sum is σ = 249858000. Its totient is φ = 55429440.

The previous prime is 138691769. The next prime is 138691801. The reversal of 138691790 is 97196831.

It is a super-2 number, since 2×138691790² = 38470825226808200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7961 + ... + 18459.

It is an arithmetic number, because the mean of its divisors is an integer number (15616125).

Almost surely, 2^138691790 is an apocalyptic number.

138691790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138691790 is a deficient number, since it is larger than the sum of its proper divisors (111166210).

138691790 is a wasteful number, since it uses less digits than its factorization.

138691790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11827.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 138691790 is about 11776.7478532912. The cubic root of 138691790 is about 517.6269955231.

The spelling of 138691790 in words is "one hundred thirty-eight million, six hundred ninety-one thousand, seven hundred ninety".