668851 has 2 divisors, whose sum is σ = 668852. Its totient is φ = 668850.

The previous prime is 668821. The next prime is 668867. The reversal of 668851 is 158866.

It is a happy number.

668851 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668851 - 2¹³ = 660659 is a prime.

It is not a weakly prime, because it can be changed into another prime (668821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334425 + 334426.

It is an arithmetic number, because the mean of its divisors is an integer number (334426).

2⁶⁶⁸⁸⁵¹ is an apocalyptic number.

668851 is a deficient number, since it is larger than the sum of its proper divisors (1).

668851 is an equidigital number, since it uses as much as digits as its factorization.

668851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 668851 is about 817.8331125603. The cubic root of 668851 is about 87.4533520062.

The spelling of 668851 in words is "six hundred sixty-eight thousand, eight hundred fifty-one".