668194287 has 4 divisors (see below), whose sum is σ = 890925720. Its totient is φ = 445462856.

The previous prime is 668194271. The next prime is 668194309. The reversal of 668194287 is 782491866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 668194287 - 2⁴ = 668194271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668194207) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111365712 + ... + 111365717.

It is an arithmetic number, because the mean of its divisors is an integer number (222731430).

Almost surely, 2^668194287 is an apocalyptic number.

668194287 is a deficient number, since it is larger than the sum of its proper divisors (222731433).

668194287 is a wasteful number, since it uses less digits than its factorization.

668194287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222731432.

The product of its digits is 1161216, while the sum is 51.

The square root of 668194287 is about 25849.4542882437. The cubic root of 668194287 is about 874.2472053724.

The spelling of 668194287 in words is "six hundred sixty-eight million, one hundred ninety-four thousand, two hundred eighty-seven".