1216122216 has 64 divisors (see below), whose sum is σ = 3195192000. Its totient is φ = 385233408.

The previous prime is 1216122209. The next prime is 1216122247. The reversal of 1216122216 is 6122216121.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 15 ways as a sum of consecutive naturals, for example, 22260 + ... + 54108.

It is an arithmetic number, because the mean of its divisors is an integer number (49924875).

Almost surely, 2^1216122216 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 1216122216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1597596000).

1216122216 is an abundant number, since it is smaller than the sum of its proper divisors (1979069784).

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

1216122216 is a wasteful number, since it uses less digits than its factorization.

1216122216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31938 (or 31934 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 1216122216 is about 34872.9438963790. The cubic root of 1216122216 is about 1067.3964172136.

Adding to 1216122216 its reverse (6122216121), we get a palindrome (7338338337).

The spelling of 1216122216 in words is "one billion, two hundred sixteen million, one hundred twenty-two thousand, two hundred sixteen".