139185913 has 4 divisors (see below), whose sum is σ = 140947840. Its totient is φ = 137423988.

The previous prime is 139185901. The next prime is 139185947. The reversal of 139185913 is 319581931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 319581931 = 643 ⋅497017.

It is a cyclic number.

It is not a de Polignac number, because 139185913 - 2⁵ = 139185881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139188913) 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, 880845 + ... + 881002.

It is an arithmetic number, because the mean of its divisors is an integer number (35236960).

Almost surely, 2^139185913 is an apocalyptic number.

It is an amenable number.

139185913 is a deficient number, since it is larger than the sum of its proper divisors (1761927).

139185913 is an equidigital number, since it uses as much as digits as its factorization.

139185913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1761926.

The product of its digits is 29160, while the sum is 40.

The square root of 139185913 is about 11797.7079553615. The cubic root of 139185913 is about 518.2409906619.

The spelling of 139185913 in words is "one hundred thirty-nine million, one hundred eighty-five thousand, nine hundred thirteen".