668401 has 8 divisors (see below), whose sum is σ = 711680. Its totient is φ = 625968.

The previous prime is 668347. The next prime is 668407. The reversal of 668401 is 104866.

668401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 668401 - 2⁷ = 668273 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (668407) 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, 2275 + ... + 2551.

It is an arithmetic number, because the mean of its divisors is an integer number (88960).

2⁶⁶⁸⁴⁰¹ is an apocalyptic number.

It is an amenable number.

668401 is a deficient number, since it is larger than the sum of its proper divisors (43279).

668401 is a wasteful number, since it uses less digits than its factorization.

668401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 668401 is about 817.5579490165. The cubic root of 668401 is about 87.4337348630.

The spelling of 668401 in words is "six hundred sixty-eight thousand, four hundred one".