331693997 has 2 divisors, whose sum is σ = 331693998. Its totient is φ = 331693996.

The previous prime is 331693961. The next prime is 331694003. The reversal of 331693997 is 799396133.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 270635401 + 61058596 = 16451^2 + 7814^2 .

It is a cyclic number.

It is not a de Polignac number, because 331693997 - 2¹⁰ = 331692973 is a prime.

It is a super-2 number, since 2×331693997² = 220041815291672018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331603997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165846998 + 165846999.

It is an arithmetic number, because the mean of its divisors is an integer number (165846999).

Almost surely, 2^331693997 is an apocalyptic number.

It is an amenable number.

331693997 is a deficient number, since it is larger than the sum of its proper divisors (1).

331693997 is an equidigital number, since it uses as much as digits as its factorization.

331693997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 826686, while the sum is 50.

The square root of 331693997 is about 18212.4681743030. The cubic root of 331693997 is about 692.2227535581. Note that the first 3 decimals are identical.

The spelling of 331693997 in words is "three hundred thirty-one million, six hundred ninety-three thousand, nine hundred ninety-seven".