668405206 has 32 divisors (see below), whose sum is σ = 1181420352. Its totient is φ = 277655040.

The previous prime is 668405203. The next prime is 668405263. The reversal of 668405206 is 602504866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668405203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86410 + ... + 93826.

It is an arithmetic number, because the mean of its divisors is an integer number (36919386).

Almost surely, 2^668405206 is an apocalyptic number.

668405206 is a deficient number, since it is larger than the sum of its proper divisors (513015146).

668405206 is a wasteful number, since it uses less digits than its factorization.

668405206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7624.

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 668405206 is about 25853.5337236518. The cubic root of 668405206 is about 874.3391825870.

The spelling of 668405206 in words is "six hundred sixty-eight million, four hundred five thousand, two hundred six".