668399166 has 48 divisors (see below), whose sum is σ = 1551919824. Its totient is φ = 207159552.

The previous prime is 668399131. The next prime is 668399177. The reversal of 668399166 is 661993866.

It is a super-3 number, since 3×668399166³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12240 + ... + 38556.

It is an arithmetic number, because the mean of its divisors is an integer number (32331663).

Almost surely, 2^668399166 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668399166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (775959912).

668399166 is an abundant number, since it is smaller than the sum of its proper divisors (883520658).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668399166 is a wasteful number, since it uses less digits than its factorization.

668399166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26425 (or 26422 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 54.

The square root of 668399166 is about 25853.4169115032. The cubic root of 668399166 is about 874.3365489427.

The spelling of 668399166 in words is "six hundred sixty-eight million, three hundred ninety-nine thousand, one hundred sixty-six".