395791661 has 2 divisors, whose sum is σ = 395791662. Its totient is φ = 395791660.

The previous prime is 395791639. The next prime is 395791699. The reversal of 395791661 is 166197593.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 232105225 + 163686436 = 15235^2 + 12794^2 .

It is a cyclic number.

It is not a de Polignac number, because 395791661 - 2¹⁴ = 395775277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (395791861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197895830 + 197895831.

It is an arithmetic number, because the mean of its divisors is an integer number (197895831).

Almost surely, 2^395791661 is an apocalyptic number.

It is an amenable number.

395791661 is a deficient number, since it is larger than the sum of its proper divisors (1).

395791661 is an equidigital number, since it uses as much as digits as its factorization.

395791661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 306180, while the sum is 47.

The square root of 395791661 is about 19894.5133391094. The cubic root of 395791661 is about 734.2132423956.

The spelling of 395791661 in words is "three hundred ninety-five million, seven hundred ninety-one thousand, six hundred sixty-one".