666344966690 has 32 divisors (see below), whose sum is σ = 1293039716976. Its totient is φ = 245776849920.

The previous prime is 666344966689. The next prime is 666344966717. The reversal of 666344966690 is 96669443666.

It can be written as a sum of positive squares in 8 ways, for example, as 189973067881 + 476371898809 = 435859^2 + 690197^2 .

It is a super-2 number, since 2×666344966690² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (65).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2565371 + ... + 2813150.

Almost surely, 2^666344966690 is an apocalyptic number.

666344966690 is a deficient number, since it is larger than the sum of its proper divisors (626694750286).

666344966690 is a wasteful number, since it uses less digits than its factorization.

666344966690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5379494.

The product of its (nonzero) digits is 181398528, while the sum is 65.

The spelling of 666344966690 in words is "six hundred sixty-six billion, three hundred forty-four million, nine hundred sixty-six thousand, six hundred ninety".