138065691 has 8 divisors (see below), whose sum is σ = 184167504. Its totient is φ = 92003840.

The previous prime is 138065659. The next prime is 138065699. The reversal of 138065691 is 196560831.

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 138065691 - 2⁵ = 138065659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138065699) 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, 690 + ... + 16631.

It is an arithmetic number, because the mean of its divisors is an integer number (23020938).

Almost surely, 2^138065691 is an apocalyptic number.

138065691 is a deficient number, since it is larger than the sum of its proper divisors (46101813).

138065691 is a wasteful number, since it uses less digits than its factorization.

138065691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19981.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 138065691 is about 11750.1357864494. The cubic root of 138065691 is about 516.8469093418.

The spelling of 138065691 in words is "one hundred thirty-eight million, sixty-five thousand, six hundred ninety-one".