168140891 has 2 divisors, whose sum is σ = 168140892. Its totient is φ = 168140890.

The previous prime is 168140887. The next prime is 168140909. The reversal of 168140891 is 198041861.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 168140891 - 2² = 168140887 is a prime.

It is not a weakly prime, because it can be changed into another prime (168140831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84070445 + 84070446.

It is an arithmetic number, because the mean of its divisors is an integer number (84070446).

Almost surely, 2^168140891 is an apocalyptic number.

168140891 is a deficient number, since it is larger than the sum of its proper divisors (1).

168140891 is an equidigital number, since it uses as much as digits as its factorization.

168140891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 38.

The square root of 168140891 is about 12966.9152461177. The cubic root of 168140891 is about 551.9390412188.

The spelling of 168140891 in words is "one hundred sixty-eight million, one hundred forty thousand, eight hundred ninety-one".