665061931 has 2 divisors, whose sum is σ = 665061932. Its totient is φ = 665061930.

The previous prime is 665061907. The next prime is 665061949. The reversal of 665061931 is 139160566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665061931 - 2¹⁵ = 665029163 is a prime.

It is a super-2 number, since 2×665061931² = 884614744130897522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (665068931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332530965 + 332530966.

It is an arithmetic number, because the mean of its divisors is an integer number (332530966).

Almost surely, 2^665061931 is an apocalyptic number.

665061931 is a deficient number, since it is larger than the sum of its proper divisors (1).

665061931 is an equidigital number, since it uses as much as digits as its factorization.

665061931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 665061931 is about 25788.7946790849. The cubic root of 665061931 is about 872.8789687123.

The spelling of 665061931 in words is "six hundred sixty-five million, sixty-one thousand, nine hundred thirty-one".