666913161 has 4 divisors (see below), whose sum is σ = 889217552. Its totient is φ = 444608772.

The previous prime is 666913157. The next prime is 666913189. The reversal of 666913161 is 161319666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 666913161 - 2² = 666913157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666913561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111152191 + ... + 111152196.

It is an arithmetic number, because the mean of its divisors is an integer number (222304388).

Almost surely, 2^666913161 is an apocalyptic number.

It is an amenable number.

666913161 is a deficient number, since it is larger than the sum of its proper divisors (222304391).

666913161 is a wasteful number, since it uses less digits than its factorization.

666913161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222304390.

The product of its digits is 34992, while the sum is 39.

The square root of 666913161 is about 25824.6618758117. The cubic root of 666913161 is about 873.6881177866.

The spelling of 666913161 in words is "six hundred sixty-six million, nine hundred thirteen thousand, one hundred sixty-one".