195911491 has 2 divisors, whose sum is σ = 195911492. Its totient is φ = 195911490.

The previous prime is 195911473. The next prime is 195911503. The reversal of 195911491 is 194119591.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 195911491 - 2⁷ = 195911363 is a prime.

It is not a weakly prime, because it can be changed into another prime (195911431) 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, 97955745 + 97955746.

It is an arithmetic number, because the mean of its divisors is an integer number (97955746).

Almost surely, 2^195911491 is an apocalyptic number.

195911491 is a deficient number, since it is larger than the sum of its proper divisors (1).

195911491 is an equidigital number, since it uses as much as digits as its factorization.

195911491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14580, while the sum is 40.

The square root of 195911491 is about 13996.8386073427. The cubic root of 195911491 is about 580.7911231479.

The spelling of 195911491 in words is "one hundred ninety-five million, nine hundred eleven thousand, four hundred ninety-one".