668691095 has 4 divisors (see below), whose sum is σ = 802429320. Its totient is φ = 534952872.

The previous prime is 668691091. The next prime is 668691097. The reversal of 668691095 is 590196866.

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 668691095 - 2² = 668691091 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668691091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66869105 + ... + 66869114.

It is an arithmetic number, because the mean of its divisors is an integer number (200607330).

Almost surely, 2^668691095 is an apocalyptic number.

668691095 is a deficient number, since it is larger than the sum of its proper divisors (133738225).

668691095 is a wasteful number, since it uses less digits than its factorization.

668691095 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133738224.

The product of its (nonzero) digits is 699840, while the sum is 50.

The square root of 668691095 is about 25859.0621446332. The cubic root of 668691095 is about 874.4638217144.

The spelling of 668691095 in words is "six hundred sixty-eight million, six hundred ninety-one thousand, ninety-five".