999866666 has 8 divisors (see below), whose sum is σ = 1499934240. Its totient is φ = 499888588.

The previous prime is 999866663. The next prime is 999866671. The reversal of 999866666 is 666668999.

It is a happy number.

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

999866666 is a modest number, since divided by 66666 gives 9998 as remainder.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (999866663) 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, 31595 + ... + 54753.

It is an arithmetic number, because the mean of its divisors is an integer number (187491780).

Almost surely, 2^999866666 is an apocalyptic number.

999866666 is a deficient number, since it is larger than the sum of its proper divisors (500067574).

999866666 is a wasteful number, since it uses less digits than its factorization.

999866666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44748.

The product of its digits is 45349632, while the sum is 65.

The square root of 999866666 is about 31620.6683357579. The cubic root of 999866666 is about 999.9555533579.

The spelling of 999866666 in words is "nine hundred ninety-nine million, eight hundred sixty-six thousand, six hundred sixty-six".