665061331 has 16 divisors (see below), whose sum is σ = 749668608. Its totient is φ = 584802400.

The previous prime is 665061289. The next prime is 665061359. The reversal of 665061331 is 133160566.

665061331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 665061331 - 2¹³ = 665053139 is a prime.

It is a super-2 number, since 2×665061331² = 884613147982983122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665061293 and 665061302.

It is not an unprimeable number, because it can be changed into a prime (665061931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33360 + ... + 49426.

It is an arithmetic number, because the mean of its divisors is an integer number (46854288).

Almost surely, 2^665061331 is an apocalyptic number.

665061331 is a deficient number, since it is larger than the sum of its proper divisors (84607277).

665061331 is a wasteful number, since it uses less digits than its factorization.

665061331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16202.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 665061331 is about 25788.7830461230. The cubic root of 665061331 is about 872.8787062167.

The spelling of 665061331 in words is "six hundred sixty-five million, sixty-one thousand, three hundred thirty-one".