166851864563 has 2 divisors, whose sum is σ = 166851864564. Its totient is φ = 166851864562.

The previous prime is 166851864551. The next prime is 166851864589. The reversal of 166851864563 is 365468158661.

It is a weak prime.

It is an emirp because it is prime and its reverse (365468158661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166851864563 - 2⁶ = 166851864499 is a prime.

It is not a weakly prime, because it can be changed into another prime (166851861563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83425932281 + 83425932282.

It is an arithmetic number, because the mean of its divisors is an integer number (83425932282).

Almost surely, 2^166851864563 is an apocalyptic number.

166851864563 is a deficient number, since it is larger than the sum of its proper divisors (1).

166851864563 is an equidigital number, since it uses as much as digits as its factorization.

166851864563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24883200, while the sum is 59.

The spelling of 166851864563 in words is "one hundred sixty-six billion, eight hundred fifty-one million, eight hundred sixty-four thousand, five hundred sixty-three".