668888807 has 4 divisors (see below), whose sum is σ = 674155776. Its totient is φ = 663621840.

The previous prime is 668888789. The next prime is 668888833. The reversal of 668888807 is 708888866.

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 668888807 - 2⁶ = 668888743 is a prime.

It is a super-2 number, since 2×668888807² = 894824472259766498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668888867) 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, 2633294 + ... + 2633547.

It is an arithmetic number, because the mean of its divisors is an integer number (168538944).

Almost surely, 2^668888807 is an apocalyptic number.

668888807 is a deficient number, since it is larger than the sum of its proper divisors (5266969).

668888807 is a wasteful number, since it uses less digits than its factorization.

668888807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5266968.

The product of its (nonzero) digits is 8257536, while the sum is 59.

The square root of 668888807 is about 25862.8847385592. The cubic root of 668888807 is about 874.5499975065.

Adding to 668888807 its sum of digits (59), we get a palindrome (668888866).

The spelling of 668888807 in words is "six hundred sixty-eight million, eight hundred eighty-eight thousand, eight hundred seven".