163813381 has 2 divisors, whose sum is σ = 163813382. Its totient is φ = 163813380.

The previous prime is 163813379. The next prime is 163813399. The reversal of 163813381 is 183318361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101324356 + 62489025 = 10066^2 + 7905^2 .

It is a cyclic number.

It is not a de Polignac number, because 163813381 - 2¹ = 163813379 is a prime.

It is a super-2 number, since 2×163813381² = 53669647589302322, which contains 22 as substring.

Together with 163813379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163813361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81906690 + 81906691.

It is an arithmetic number, because the mean of its divisors is an integer number (81906691).

Almost surely, 2^163813381 is an apocalyptic number.

It is an amenable number.

163813381 is a deficient number, since it is larger than the sum of its proper divisors (1).

163813381 is an equidigital number, since it uses as much as digits as its factorization.

163813381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 163813381 is about 12798.9601530749. The cubic root of 163813381 is about 547.1626673148.

The spelling of 163813381 in words is "one hundred sixty-three million, eight hundred thirteen thousand, three hundred eighty-one".