195012091 has 2 divisors, whose sum is σ = 195012092. Its totient is φ = 195012090.

The previous prime is 195012061. The next prime is 195012109. The reversal of 195012091 is 190210591.

Together with next prime (195012109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-195012091 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (195012061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97506045 + 97506046.

It is an arithmetic number, because the mean of its divisors is an integer number (97506046).

Almost surely, 2^195012091 is an apocalyptic number.

195012091 is a deficient number, since it is larger than the sum of its proper divisors (1).

195012091 is an equidigital number, since it uses as much as digits as its factorization.

195012091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 810, while the sum is 28.

The square root of 195012091 is about 13964.6729643053. The cubic root of 195012091 is about 579.9009848811.

It can be divided in two parts, 1950 and 12091, that added together give a palindrome (14041).

The spelling of 195012091 in words is "one hundred ninety-five million, twelve thousand, ninety-one".