195521243 has 2 divisors, whose sum is σ = 195521244. Its totient is φ = 195521242.

The previous prime is 195521213. The next prime is 195521279. The reversal of 195521243 is 342125591.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 195521243 - 2²⁰ = 194472667 is a prime.

It is not a weakly prime, because it can be changed into another prime (195521213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97760621 + 97760622.

It is an arithmetic number, because the mean of its divisors is an integer number (97760622).

Almost surely, 2^195521243 is an apocalyptic number.

195521243 is a deficient number, since it is larger than the sum of its proper divisors (1).

195521243 is an equidigital number, since it uses as much as digits as its factorization.

195521243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 32.

The square root of 195521243 is about 13982.8910816040. The cubic root of 195521243 is about 580.4052290993.

The spelling of 195521243 in words is "one hundred ninety-five million, five hundred twenty-one thousand, two hundred forty-three".