163643813 has 2 divisors, whose sum is σ = 163643814. Its totient is φ = 163643812.

The previous prime is 163643791. The next prime is 163643849. The reversal of 163643813 is 318346361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120846049 + 42797764 = 10993^2 + 6542^2 .

It is a cyclic number.

It is not a de Polignac number, because 163643813 - 2¹⁰ = 163642789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163643863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81821906 + 81821907.

It is an arithmetic number, because the mean of its divisors is an integer number (81821907).

Almost surely, 2^163643813 is an apocalyptic number.

It is an amenable number.

163643813 is a deficient number, since it is larger than the sum of its proper divisors (1).

163643813 is an equidigital number, since it uses as much as digits as its factorization.

163643813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 35.

The square root of 163643813 is about 12792.3341497946. The cubic root of 163643813 is about 546.9738074659.

The spelling of 163643813 in words is "one hundred sixty-three million, six hundred forty-three thousand, eight hundred thirteen".