666161894 has 16 divisors (see below), whose sum is σ = 1010240640. Its totient is φ = 329427840.

The previous prime is 666161851. The next prime is 666161911. The reversal of 666161894 is 498161666.

It is a Curzon number.

It is a congruent number.

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, 112139 + ... + 117929.

It is an arithmetic number, because the mean of its divisors is an integer number (63140040).

Almost surely, 2^666161894 is an apocalyptic number.

666161894 is a deficient number, since it is larger than the sum of its proper divisors (344078746).

666161894 is a wasteful number, since it uses less digits than its factorization.

666161894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6415.

The product of its digits is 373248, while the sum is 47.

The square root of 666161894 is about 25810.1122430725. The cubic root of 666161894 is about 873.3599292964.

The spelling of 666161894 in words is "six hundred sixty-six million, one hundred sixty-one thousand, eight hundred ninety-four".