195319661 has 2 divisors, whose sum is σ = 195319662. Its totient is φ = 195319660.

The previous prime is 195319637. The next prime is 195319699. The reversal of 195319661 is 166913591.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154231561 + 41088100 = 12419^2 + 6410^2 .

It is a cyclic number.

It is not a de Polignac number, because 195319661 - 2¹⁸ = 195057517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (195319261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97659830 + 97659831.

It is an arithmetic number, because the mean of its divisors is an integer number (97659831).

Almost surely, 2^195319661 is an apocalyptic number.

It is an amenable number.

195319661 is a deficient number, since it is larger than the sum of its proper divisors (1).

195319661 is an equidigital number, since it uses as much as digits as its factorization.

195319661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43740, while the sum is 41.

The square root of 195319661 is about 13975.6810567500. The cubic root of 195319661 is about 580.2056949774.

It can be divided in two parts, 19531 and 9661, that added together give a palindrome (29192).

The spelling of 195319661 in words is "one hundred ninety-five million, three hundred nineteen thousand, six hundred sixty-one".