668407 has 2 divisors, whose sum is σ = 668408. Its totient is φ = 668406.

The previous prime is 668347. The next prime is 668417. The reversal of 668407 is 704866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668407 - 2¹⁵ = 635639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334203 + 334204.

It is an arithmetic number, because the mean of its divisors is an integer number (334204).

2⁶⁶⁸⁴⁰⁷ is an apocalyptic number.

668407 is a deficient number, since it is larger than the sum of its proper divisors (1).

668407 is an equidigital number, since it uses as much as digits as its factorization.

668407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 668407 is about 817.5616184729. The cubic root of 668407 is about 87.4339964829.

The spelling of 668407 in words is "six hundred sixty-eight thousand, four hundred seven".