331666645 has 4 divisors (see below), whose sum is σ = 397999980. Its totient is φ = 265333312.

The previous prime is 331666627. The next prime is 331666663. The reversal of 331666645 is 546666133.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (331666627) and next prime (331666663).

It can be written as a sum of positive squares in 2 ways, for example, as 170224209 + 161442436 = 13047^2 + 12706^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-331666645 is a prime.

It is a super-2 number, since 2×331666645² = 220005526811112050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 331666598 and 331666607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33166660 + ... + 33166669.

It is an arithmetic number, because the mean of its divisors is an integer number (99499995).

Almost surely, 2^331666645 is an apocalyptic number.

It is an amenable number.

331666645 is a deficient number, since it is larger than the sum of its proper divisors (66333335).

331666645 is an equidigital number, since it uses as much as digits as its factorization.

331666645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66333334.

The product of its digits is 233280, while the sum is 40.

The square root of 331666645 is about 18211.7172446752. The cubic root of 331666645 is about 692.2037257822.

The spelling of 331666645 in words is "three hundred thirty-one million, six hundred sixty-six thousand, six hundred forty-five".