2216631816 has 144 divisors (see below), whose sum is σ = 7172687340. Its totient is φ = 616170240.

The previous prime is 2216631803. The next prime is 2216631869. The reversal of 2216631816 is 6181366122.

It is a happy number.

2216631816 is a `hidden beast` number, since 2 + 2 + 1 + 6 + 631 + 8 + 16 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1608812100 + 607819716 = 40110^2 + 24654^2 .

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 an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 122046 + ... + 139026.

Almost surely, 2^2216631816 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 2216631816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3586343670).

2216631816 is an abundant number, since it is smaller than the sum of its proper divisors (4956055524).

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

2216631816 is a wasteful number, since it uses less digits than its factorization.

2216631816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17044 (or 17030 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 2216631816 is about 47081.1195278957. The cubic root of 2216631816 is about 1303.8606764593.

Adding to 2216631816 its reverse (6181366122), we get a palindrome (8397997938).

The spelling of 2216631816 in words is "two billion, two hundred sixteen million, six hundred thirty-one thousand, eight hundred sixteen".