668140667 has 4 divisors (see below), whose sum is σ = 668332896. Its totient is φ = 667948440.

The previous prime is 668140609. The next prime is 668140699. The reversal of 668140667 is 766041866.

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 668140667 - 2¹² = 668136571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668142667) 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, 90803 + ... + 97884.

It is an arithmetic number, because the mean of its divisors is an integer number (167083224).

Almost surely, 2^668140667 is an apocalyptic number.

668140667 is a deficient number, since it is larger than the sum of its proper divisors (192229).

668140667 is a wasteful number, since it uses less digits than its factorization.

668140667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192228.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 668140667 is about 25848.4171082099. The cubic root of 668140667 is about 874.2238197644.

The spelling of 668140667 in words is "six hundred sixty-eight million, one hundred forty thousand, six hundred sixty-seven".