331665109 has 2 divisors, whose sum is σ = 331665110. Its totient is φ = 331665108.

The previous prime is 331665107. The next prime is 331665133. The reversal of 331665109 is 901566133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 331604100 + 61009 = 18210^2 + 247^2 .

It is a cyclic number.

It is not a de Polignac number, because 331665109 - 2¹ = 331665107 is a prime.

It is a super-2 number, since 2×331665109² = 220003489055963762, which contains 22 as substring.

Together with 331665107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331665107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165832554 + 165832555.

It is an arithmetic number, because the mean of its divisors is an integer number (165832555).

Almost surely, 2^331665109 is an apocalyptic number.

It is an amenable number.

331665109 is a deficient number, since it is larger than the sum of its proper divisors (1).

331665109 is an equidigital number, since it uses as much as digits as its factorization.

331665109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 34.

The square root of 331665109 is about 18211.6750739738. The cubic root of 331665109 is about 692.2026572127.

The spelling of 331665109 in words is "three hundred thirty-one million, six hundred sixty-five thousand, one hundred nine".