163664861 has 2 divisors, whose sum is σ = 163664862. Its totient is φ = 163664860.

The previous prime is 163664833. The next prime is 163664867. The reversal of 163664861 is 168466361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148376761 + 15288100 = 12181^2 + 3910^2 .

It is a cyclic number.

It is not a de Polignac number, because 163664861 - 2²⁶ = 96555997 is a prime.

It is a super-2 number, since 2×163664861² = 53572373452298642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163664867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81832430 + 81832431.

It is an arithmetic number, because the mean of its divisors is an integer number (81832431).

Almost surely, 2^163664861 is an apocalyptic number.

It is an amenable number.

163664861 is a deficient number, since it is larger than the sum of its proper divisors (1).

163664861 is an equidigital number, since it uses as much as digits as its factorization.

163664861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 41.

The square root of 163664861 is about 12793.1568035415. The cubic root of 163664861 is about 546.9972571989.

The spelling of 163664861 in words is "one hundred sixty-three million, six hundred sixty-four thousand, eight hundred sixty-one".