195139999 has 2 divisors, whose sum is σ = 195140000. Its totient is φ = 195139998.

The previous prime is 195139943. The next prime is 195140017. The reversal of 195139999 is 999931591.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-195139999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (195139909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97569999 + 97570000.

It is an arithmetic number, because the mean of its divisors is an integer number (97570000).

Almost surely, 2^195139999 is an apocalyptic number.

195139999 is a deficient number, since it is larger than the sum of its proper divisors (1).

195139999 is an equidigital number, since it uses as much as digits as its factorization.

195139999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 885735, while the sum is 55.

The square root of 195139999 is about 13969.2519126831. The cubic root of 195139999 is about 580.0277424304.

The spelling of 195139999 in words is "one hundred ninety-five million, one hundred thirty-nine thousand, nine hundred ninety-nine".