168220691 has 2 divisors, whose sum is σ = 168220692. Its totient is φ = 168220690.

The previous prime is 168220673. The next prime is 168220693. The reversal of 168220691 is 196022861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 168220691 - 2²⁶ = 101111827 is a prime.

Together with 168220693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (168220693) 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, 84110345 + 84110346.

It is an arithmetic number, because the mean of its divisors is an integer number (84110346).

Almost surely, 2^168220691 is an apocalyptic number.

168220691 is a deficient number, since it is larger than the sum of its proper divisors (1).

168220691 is an equidigital number, since it uses as much as digits as its factorization.

168220691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 168220691 is about 12969.9919429428. The cubic root of 168220691 is about 552.0263445296.

The spelling of 168220691 in words is "one hundred sixty-eight million, two hundred twenty thousand, six hundred ninety-one".