665461266 has 16 divisors (see below), whose sum is σ = 1338894144. Its totient is φ = 220491824.

The previous prime is 665461259. The next prime is 665461309. The reversal of 665461266 is 662164566.

It is a happy number.

It is a super-4 number, since 4×665461266⁴ (a number of 36 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 331065 + ... + 333068.

It is an arithmetic number, because the mean of its divisors is an integer number (83680884).

Almost surely, 2^665461266 is an apocalyptic number.

665461266 is an abundant number, since it is smaller than the sum of its proper divisors (673432878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665461266 is a wasteful number, since it uses less digits than its factorization.

665461266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664305.

The product of its digits is 311040, while the sum is 42.

The square root of 665461266 is about 25796.5359302368. The cubic root of 665461266 is about 873.0536398538.

The spelling of 665461266 in words is "six hundred sixty-five million, four hundred sixty-one thousand, two hundred sixty-six".