139642931 has 2 divisors, whose sum is σ = 139642932. Its totient is φ = 139642930.

The previous prime is 139642907. The next prime is 139642939. The reversal of 139642931 is 139246931.

It is a strong prime.

It is an emirp because it is prime and its reverse (139246931) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139642931 is a prime.

It is a super-2 number, since 2×139642931² = 39000296356541522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139642939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69821465 + 69821466.

It is an arithmetic number, because the mean of its divisors is an integer number (69821466).

Almost surely, 2^139642931 is an apocalyptic number.

139642931 is a deficient number, since it is larger than the sum of its proper divisors (1).

139642931 is an equidigital number, since it uses as much as digits as its factorization.

139642931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 38.

The square root of 139642931 is about 11817.0610136362. The cubic root of 139642931 is about 518.8075870458.

The spelling of 139642931 in words is "one hundred thirty-nine million, six hundred forty-two thousand, nine hundred thirty-one".