668002891 has 2 divisors, whose sum is σ = 668002892. Its totient is φ = 668002890.

The previous prime is 668002883. The next prime is 668002943. The reversal of 668002891 is 198200866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668002891 - 2³ = 668002883 is a prime.

It is not a weakly prime, because it can be changed into another prime (668009891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334001445 + 334001446.

It is an arithmetic number, because the mean of its divisors is an integer number (334001446).

Almost surely, 2^668002891 is an apocalyptic number.

668002891 is a deficient number, since it is larger than the sum of its proper divisors (1).

668002891 is an equidigital number, since it uses as much as digits as its factorization.

668002891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 668002891 is about 25845.7518946538. The cubic root of 668002891 is about 874.1637249635.

The spelling of 668002891 in words is "six hundred sixty-eight million, two thousand, eight hundred ninety-one".