168861691 has 2 divisors, whose sum is σ = 168861692. Its totient is φ = 168861690.

The previous prime is 168861689. The next prime is 168861733. The reversal of 168861691 is 196168861.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 168861691 - 2¹ = 168861689 is a prime.

Together with 168861689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (168861661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84430845 + 84430846.

It is an arithmetic number, because the mean of its divisors is an integer number (84430846).

Almost surely, 2^168861691 is an apocalyptic number.

168861691 is a deficient number, since it is larger than the sum of its proper divisors (1).

168861691 is an equidigital number, since it uses as much as digits as its factorization.

168861691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 46.

The square root of 168861691 is about 12994.6793342506. The cubic root of 168861691 is about 552.7266158818.

The spelling of 168861691 in words is "one hundred sixty-eight million, eight hundred sixty-one thousand, six hundred ninety-one".