163681818 has 16 divisors (see below), whose sum is σ = 327492480. Its totient is φ = 54539136.

The previous prime is 163681811. The next prime is 163681883. The reversal of 163681818 is 818186361.

It is a self number, because there is not a number n which added to its sum of digits gives 163681818.

It is not an unprimeable number, because it can be changed into a prime (163681811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21471 + ... + 28077.

It is an arithmetic number, because the mean of its divisors is an integer number (20468280).

Almost surely, 2^163681818 is an apocalyptic number.

163681818 is an abundant number, since it is smaller than the sum of its proper divisors (163810662).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

163681818 is a wasteful number, since it uses less digits than its factorization.

163681818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10741.

The product of its digits is 55296, while the sum is 42.

The square root of 163681818 is about 12793.8195235043. The cubic root of 163681818 is about 547.0161476561.

The spelling of 163681818 in words is "one hundred sixty-three million, six hundred eighty-one thousand, eight hundred eighteen".