195390857 has 2 divisors, whose sum is σ = 195390858. Its totient is φ = 195390856.

The previous prime is 195390847. The next prime is 195390901. The reversal of 195390857 is 758093591.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187032976 + 8357881 = 13676^2 + 2891^2 .

It is an emirp because it is prime and its reverse (758093591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 195390857 - 2¹² = 195386761 is a prime.

It is not a weakly prime, because it can be changed into another prime (195390847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97695428 + 97695429.

It is an arithmetic number, because the mean of its divisors is an integer number (97695429).

Almost surely, 2^195390857 is an apocalyptic number.

It is an amenable number.

195390857 is a deficient number, since it is larger than the sum of its proper divisors (1).

195390857 is an equidigital number, since it uses as much as digits as its factorization.

195390857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 340200, while the sum is 47.

The square root of 195390857 is about 13978.2279635153. The cubic root of 195390857 is about 580.2761833695.

The spelling of 195390857 in words is "one hundred ninety-five million, three hundred ninety thousand, eight hundred fifty-seven".