195997931 has 2 divisors, whose sum is σ = 195997932. Its totient is φ = 195997930.

The previous prime is 195997889. The next prime is 195997933. The reversal of 195997931 is 139799591.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 195997931 - 2²² = 191803627 is a prime.

It is a super-3 number, since 3×195997931³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 195997933, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (195997933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97998965 + 97998966.

It is an arithmetic number, because the mean of its divisors is an integer number (97998966).

Almost surely, 2^195997931 is an apocalyptic number.

195997931 is a deficient number, since it is larger than the sum of its proper divisors (1).

195997931 is an equidigital number, since it uses as much as digits as its factorization.

195997931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 688905, while the sum is 53.

The square root of 195997931 is about 13999.9261069479. The cubic root of 195997931 is about 580.8765294074.

The spelling of 195997931 in words is "one hundred ninety-five million, nine hundred ninety-seven thousand, nine hundred thirty-one".