331693661 has 12 divisors (see below), whose sum is σ = 363213396. Its totient is φ = 301115520.

The previous prime is 331693657. The next prime is 331693667. The reversal of 331693661 is 166396133.

It can be written as a sum of positive squares in 6 ways, for example, as 276191161 + 55502500 = 16619^2 + 7450^2 .

It is not a de Polignac number, because 331693661 - 2² = 331693657 is a prime.

It is a super-2 number, since 2×331693661² = 220041369495165842, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331693667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44945 + ... + 51801.

It is an arithmetic number, because the mean of its divisors is an integer number (30267783).

Almost surely, 2^331693661 is an apocalyptic number.

It is an amenable number.

331693661 is a deficient number, since it is larger than the sum of its proper divisors (31519735).

331693661 is an equidigital number, since it uses as much as digits as its factorization.

331693661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6992 (or 6931 counting only the distinct ones).

The product of its digits is 52488, while the sum is 38.

The square root of 331693661 is about 18212.4589498508. The cubic root of 331693661 is about 692.2225198217. Note that the first 3 decimals are identical.

The spelling of 331693661 in words is "three hundred thirty-one million, six hundred ninety-three thousand, six hundred sixty-one".