331991030981 has 2 divisors, whose sum is σ = 331991030982. Its totient is φ = 331991030980.

The previous prime is 331991030957. The next prime is 331991031013. The reversal of 331991030981 is 189030199133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174215246881 + 157775784100 = 417391^2 + 397210^2 .

It is a cyclic number.

It is not a de Polignac number, because 331991030981 - 2²² = 331986836677 is a prime.

It is a super-2 number, since 2×331991030981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331991030911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165995515490 + 165995515491.

It is an arithmetic number, because the mean of its divisors is an integer number (165995515491).

Almost surely, 2^331991030981 is an apocalyptic number.

It is an amenable number.

331991030981 is a deficient number, since it is larger than the sum of its proper divisors (1).

331991030981 is an equidigital number, since it uses as much as digits as its factorization.

331991030981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 157464, while the sum is 47.

The spelling of 331991030981 in words is "three hundred thirty-one billion, nine hundred ninety-one million, thirty thousand, nine hundred eighty-one".