331663997 has 6 divisors (see below), whose sum is σ = 385813278. Its totient is φ = 284283384.

The previous prime is 331663973. The next prime is 331664027. The reversal of 331663997 is 799366133.

It can be written as a sum of positive squares in only one way, i.e., 268763236 + 62900761 = 16394^2 + 7931^2 .

It is not a de Polignac number, because 331663997 - 2¹⁶ = 331598461 is a prime.

It is a super-2 number, since 2×331663997² = 220002013812032018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331663097) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3384278 + ... + 3384375.

It is an arithmetic number, because the mean of its divisors is an integer number (64302213).

Almost surely, 2^331663997 is an apocalyptic number.

It is an amenable number.

331663997 is a deficient number, since it is larger than the sum of its proper divisors (54149281).

331663997 is an equidigital number, since it uses as much as digits as its factorization.

331663997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6768667 (or 6768660 counting only the distinct ones).

The product of its digits is 551124, while the sum is 47.

The square root of 331663997 is about 18211.6445440822. The cubic root of 331663997 is about 692.2018836108.

The spelling of 331663997 in words is "three hundred thirty-one million, six hundred sixty-three thousand, nine hundred ninety-seven".