211818816 has 168 divisors, whose sum is σ = 670913568. Its totient is φ = 63360000.

The previous prime is 211818811. The next prime is 211818857. The reversal of 211818816 is 618818112.

It is a happy number.

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (211818811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 639771 + ... + 640101.

Almost surely, 2^211818816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211818816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335456784).

211818816 is an abundant number, since it is smaller than the sum of its proper divisors (459094752).

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

211818816 is a wasteful number, since it uses less digits than its factorization.

211818816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 448 counting only the distinct ones).

The product of its digits is 6144, while the sum is 36.

The square root of 211818816 is about 14553.9965645179. The cubic root of 211818816 is about 596.1032807517.

The spelling of 211818816 in words is "two hundred eleven million, eight hundred eighteen thousand, eight hundred sixteen".