668181 has 8 divisors (see below), whose sum is σ = 903744. Its totient is φ = 439040.

The previous prime is 668179. The next prime is 668201. The reversal of 668181 is 181866.

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 668181 - 2¹ = 668179 is a prime.

It is a super-2 number, since 2×668181² = 892931697522, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 668181.

It is not an unprimeable number, because it can be changed into a prime (668111) 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, 1356 + ... + 1781.

It is an arithmetic number, because the mean of its divisors is an integer number (112968).

2⁶⁶⁸¹⁸¹ is an apocalyptic number.

It is an amenable number.

668181 is a deficient number, since it is larger than the sum of its proper divisors (235563).

668181 is a wasteful number, since it uses less digits than its factorization.

668181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3211.

The product of its digits is 2304, while the sum is 30.

The square root of 668181 is about 817.4233909058. The cubic root of 668181 is about 87.4241410551.

The spelling of 668181 in words is "six hundred sixty-eight thousand, one hundred eighty-one".