38139691 has 4 divisors (see below), whose sum is σ = 38162800. Its totient is φ = 38116584.

The previous prime is 38139677. The next prime is 38139697. The reversal of 38139691 is 19693183.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19693183 = 43 ⋅457981.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-38139691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (38139697) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8871 + ... + 12448.

It is an arithmetic number, because the mean of its divisors is an integer number (9540700).

Almost surely, 2^38139691 is an apocalyptic number.

38139691 is a deficient number, since it is larger than the sum of its proper divisors (23109).

38139691 is a wasteful number, since it uses less digits than its factorization.

38139691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23108.

The product of its digits is 34992, while the sum is 40.

The square root of 38139691 is about 6175.7340454395. The cubic root of 38139691 is about 336.6089998061.

The spelling of 38139691 in words is "thirty-eight million, one hundred thirty-nine thousand, six hundred ninety-one".