195919391 has 4 divisors (see below), whose sum is σ = 195978000. Its totient is φ = 195860784.

The previous prime is 195919379. The next prime is 195919397. The reversal of 195919391 is 193919591.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193919591 = 4099 ⋅47309.

It is a cyclic number.

It is not a de Polignac number, because 195919391 - 2¹⁴ = 195903007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195919397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23966 + ... + 31083.

It is an arithmetic number, because the mean of its divisors is an integer number (48994500).

Almost surely, 2^195919391 is an apocalyptic number.

195919391 is a deficient number, since it is larger than the sum of its proper divisors (58609).

195919391 is an equidigital number, since it uses as much as digits as its factorization.

195919391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58608.

The product of its digits is 98415, while the sum is 47.

The square root of 195919391 is about 13997.1208110811. The cubic root of 195919391 is about 580.7989297144.

It can be divided in two parts, 19591 and 9391, that added together give a palindrome (28982).

The spelling of 195919391 in words is "one hundred ninety-five million, nine hundred nineteen thousand, three hundred ninety-one".