666667406 has 12 divisors (see below), whose sum is σ = 1027762848. Its totient is φ = 324323352.

The previous prime is 666667403. The next prime is 666667433. The reversal of 666667406 is 604766666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666667403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 119006 + ... + 124481.

It is an arithmetic number, because the mean of its divisors is an integer number (85646904).

Almost surely, 2^666667406 is an apocalyptic number.

666667406 is a deficient number, since it is larger than the sum of its proper divisors (361095442).

666667406 is a wasteful number, since it uses less digits than its factorization.

666667406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243563 (or 243526 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 47.

The square root of 666667406 is about 25819.9032918406. The cubic root of 666667406 is about 873.5807876698.

The spelling of 666667406 in words is "six hundred sixty-six million, six hundred sixty-seven thousand, four hundred six".