163994974643 has 2 divisors, whose sum is σ = 163994974644. Its totient is φ = 163994974642.

The previous prime is 163994974609. The next prime is 163994974687. The reversal of 163994974643 is 346479499361.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 163994974643 - 2⁸ = 163994974387 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 163994974643.

It is not a weakly prime, because it can be changed into another prime (163994974543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81997487321 + 81997487322.

It is an arithmetic number, because the mean of its divisors is an integer number (81997487322).

Almost surely, 2^163994974643 is an apocalyptic number.

163994974643 is a deficient number, since it is larger than the sum of its proper divisors (1).

163994974643 is an equidigital number, since it uses as much as digits as its factorization.

163994974643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 105815808, while the sum is 65.

The spelling of 163994974643 in words is "one hundred sixty-three billion, nine hundred ninety-four million, nine hundred seventy-four thousand, six hundred forty-three".