216663336 has 80 divisors (see below), whose sum is σ = 609687540. Its totient is φ = 71884800.

The previous prime is 216663329. The next prime is 216663341. The reversal of 216663336 is 633366612.

It is a happy number.

216663336 is a nontrivial binomial coefficient, being equal to C(20817, 2).

It can be written as a sum of positive squares in 2 ways, for example, as 216266436 + 396900 = 14706^2 + 630^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 216663336.

It is a congruent number.

It is an unprimeable number.

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 in 19 ways as a sum of consecutive naturals, for example, 165886 + ... + 167186.

Almost surely, 2^216663336 is an apocalyptic number.

216663336 is the 20816-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216663336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304843770).

216663336 is an abundant number, since it is smaller than the sum of its proper divisors (393024204).

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

216663336 is a wasteful number, since it uses less digits than its factorization.

216663336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1576 (or 1563 counting only the distinct ones).

The product of its digits is 69984, while the sum is 36.

The square root of 216663336 is about 14719.4883063237. The cubic root of 216663336 is about 600.6135723344.

The spelling of 216663336 in words is "two hundred sixteen million, six hundred sixty-three thousand, three hundred thirty-six".