168364195921 has 2 divisors, whose sum is σ = 168364195922. Its totient is φ = 168364195920.

The previous prime is 168364195907. The next prime is 168364195997. The reversal of 168364195921 is 129591463861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 146677510225 + 21686685696 = 382985^2 + 147264^2 .

It is a cyclic number.

It is not a de Polignac number, because 168364195921 - 2¹⁹ = 168363671633 is a prime.

It is not a weakly prime, because it can be changed into another prime (168364195121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84182097960 + 84182097961.

It is an arithmetic number, because the mean of its divisors is an integer number (84182097961).

Almost surely, 2^168364195921 is an apocalyptic number.

It is an amenable number.

168364195921 is a deficient number, since it is larger than the sum of its proper divisors (1).

168364195921 is an equidigital number, since it uses as much as digits as its factorization.

168364195921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 55.

The spelling of 168364195921 in words is "one hundred sixty-eight billion, three hundred sixty-four million, one hundred ninety-five thousand, nine hundred twenty-one".