666831871 has 8 divisors (see below), whose sum is σ = 690919344. Its totient is φ = 643063680.

The previous prime is 666831863. The next prime is 666831881. The reversal of 666831871 is 178138666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666831871 - 2³ = 666831863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666831881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75565 + ... + 83926.

It is an arithmetic number, because the mean of its divisors is an integer number (86364918).

Almost surely, 2^666831871 is an apocalyptic number.

666831871 is a deficient number, since it is larger than the sum of its proper divisors (24087473).

666831871 is a wasteful number, since it uses less digits than its factorization.

666831871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159641.

The product of its digits is 290304, while the sum is 46.

The square root of 666831871 is about 25823.0879447056. The cubic root of 666831871 is about 873.6526184157.

The spelling of 666831871 in words is "six hundred sixty-six million, eight hundred thirty-one thousand, eight hundred seventy-one".