311968661 has 2 divisors, whose sum is σ = 311968662. Its totient is φ = 311968660.

The previous prime is 311968633. The next prime is 311968673. The reversal of 311968661 is 166869113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 267159025 + 44809636 = 16345^2 + 6694^2 .

It is an emirp because it is prime and its reverse (166869113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 311968661 - 2¹⁰ = 311967637 is a prime.

It is a super-2 number, since 2×311968661² = 194648890892265842, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311968061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155984330 + 155984331.

It is an arithmetic number, because the mean of its divisors is an integer number (155984331).

Almost surely, 2^311968661 is an apocalyptic number.

It is an amenable number.

311968661 is a deficient number, since it is larger than the sum of its proper divisors (1).

311968661 is an equidigital number, since it uses as much as digits as its factorization.

311968661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 41.

The square root of 311968661 is about 17662.6345996287. The cubic root of 311968661 is about 678.2195790443.

The spelling of 311968661 in words is "three hundred eleven million, nine hundred sixty-eight thousand, six hundred sixty-one".