1216633320 has 192 divisors, whose sum is σ = 4536155520. Its totient is φ = 277028352.

The previous prime is 1216633309. The next prime is 1216633321. The reversal of 1216633320 is 233366121.

It is a happy number.

1216633320 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 633 + 3 + 20 = 666.

It is not an unprimeable number, because it can be changed into a prime (1216633321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 798079 + ... + 799601.

It is an arithmetic number, because the mean of its divisors is an integer number (23625810).

Almost surely, 2^1216633320 is an apocalyptic number.

1216633320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216633320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2268077760).

1216633320 is an abundant number, since it is smaller than the sum of its proper divisors (3319522200).

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

1216633320 is a wasteful number, since it uses less digits than its factorization.

1216633320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1864 (or 1857 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 1216633320 is about 34880.2712145419. The cubic root of 1216633320 is about 1067.5459290972.

Adding to 1216633320 its reverse (233366121), we get a palindrome (1449999441).

The spelling of 1216633320 in words is "one billion, two hundred sixteen million, six hundred thirty-three thousand, three hundred twenty".