138691766 has 16 divisors (see below), whose sum is σ = 215193888. Its totient is φ = 66993600.

The previous prime is 138691757. The next prime is 138691769. The reversal of 138691766 is 667196831.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 138691766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138691769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236 + ... + 16656.

It is an arithmetic number, because the mean of its divisors is an integer number (13449618).

Almost surely, 2^138691766 is an apocalyptic number.

138691766 is a deficient number, since it is larger than the sum of its proper divisors (76502122).

138691766 is a wasteful number, since it uses less digits than its factorization.

138691766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16567.

The product of its digits is 326592, while the sum is 47.

The square root of 138691766 is about 11776.7468343342. The cubic root of 138691766 is about 517.6269656654.

The spelling of 138691766 in words is "one hundred thirty-eight million, six hundred ninety-one thousand, seven hundred sixty-six".