331959795921661 has 2 divisors, whose sum is σ = 331959795921662. Its totient is φ = 331959795921660.

The previous prime is 331959795921557. The next prime is 331959795921667. The reversal of 331959795921661 is 166129597959133.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202358989386436 + 129600806535225 = 14225294^2 + 11384235^2 .

It is a cyclic number.

It is not a de Polignac number, because 331959795921661 - 2²¹ = 331959793824509 is a prime.

It is a super-2 number, since 2×331959795921661² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331959795921667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165979897960830 + 165979897960831.

It is an arithmetic number, because the mean of its divisors is an integer number (165979897960831).

Almost surely, 2^{331959795921661} is an apocalyptic number.

It is an amenable number.

331959795921661 is a deficient number, since it is larger than the sum of its proper divisors (1).

331959795921661 is an equidigital number, since it uses as much as digits as its factorization.

331959795921661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 744017400, while the sum is 76.

The spelling of 331959795921661 in words is "three hundred thirty-one trillion, nine hundred fifty-nine billion, seven hundred ninety-five million, nine hundred twenty-one thousand, six hundred sixty-one".