668156 has 6 divisors (see below), whose sum is σ = 1169280. Its totient is φ = 334076.

The previous prime is 668153. The next prime is 668159. The reversal of 668156 is 651866.

It is an interprime number because it is at equal distance from previous prime (668153) and next prime (668159).

It is an Ulam number.

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 668156.

It is not an unprimeable number, because it can be changed into a prime (668153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83516 + ... + 83523.

It is an arithmetic number, because the mean of its divisors is an integer number (194880).

2⁶⁶⁸¹⁵⁶ is an apocalyptic number.

It is an amenable number.

668156 is a deficient number, since it is larger than the sum of its proper divisors (501124).

668156 is a wasteful number, since it uses less digits than its factorization.

668156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167043 (or 167041 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

The square root of 668156 is about 817.4080988099. The cubic root of 668156 is about 87.4230507164.

Subtracting from 668156 its reverse (651866), we obtain a triangular number (16290 = T₁₈₀).

The spelling of 668156 in words is "six hundred sixty-eight thousand, one hundred fifty-six".