665668826 has 16 divisors (see below), whose sum is σ = 1004849664. Its totient is φ = 330724944.

The previous prime is 665668799. The next prime is 665668837. The reversal of 665668826 is 628866566.

It is a super-2 number, since 2×665668826² = 886229971816436552, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323216 + ... + 325268.

It is an arithmetic number, because the mean of its divisors is an integer number (62803104).

Almost surely, 2^665668826 is an apocalyptic number.

665668826 is a deficient number, since it is larger than the sum of its proper divisors (339180838).

665668826 is a wasteful number, since it uses less digits than its factorization.

665668826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3005.

The product of its digits is 4976640, while the sum is 53.

The square root of 665668826 is about 25800.5586373629. The cubic root of 665668826 is about 873.1444000457.

The spelling of 665668826 in words is "six hundred sixty-five million, six hundred sixty-eight thousand, eight hundred twenty-six".