218161812 has 24 divisors (see below), whose sum is σ = 555321312. Its totient is φ = 66109600.

The previous prime is 218161807. The next prime is 218161813.

It is a happy number.

218161812 is nontrivially palindromic in base 10.

218161812 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 218161812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218161813) 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, 826239 + ... + 826502.

It is an arithmetic number, because the mean of its divisors is an integer number (23138388).

Almost surely, 2^218161812 is an apocalyptic number.

218161812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

218161812 is an abundant number, since it is smaller than the sum of its proper divisors (337159500).

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

218161812 is a wasteful number, since it uses less digits than its factorization.

218161812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1652759 (or 1652757 counting only the distinct ones).

The product of its digits is 1536, while the sum is 30.

The square root of 218161812 is about 14770.3016895390. The cubic root of 218161812 is about 601.9950368056.

The spelling of 218161812 in words is "two hundred eighteen million, one hundred sixty-one thousand, eight hundred twelve".