1216544616 has 512 divisors, whose sum is σ = 4478976000. Its totient is φ = 297603072.

The previous prime is 1216544603. The next prime is 1216544617. The reversal of 1216544616 is 6164456121.

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

It is not an unprimeable number, because it can be changed into a prime (1216544617) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 22953646 + ... + 22953698.

It is an arithmetic number, because the mean of its divisors is an integer number (8748000).

Almost surely, 2^1216544616 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 1216544616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2239488000).

1216544616 is an abundant number, since it is smaller than the sum of its proper divisors (3262431384).

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

1216544616 is a wasteful number, since it uses less digits than its factorization.

1216544616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 148 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1216544616 is about 34878.9996416182. Note that the first 3 decimals coincide. The cubic root of 1216544616 is about 1067.5199837571.

The spelling of 1216544616 in words is "one billion, two hundred sixteen million, five hundred forty-four thousand, six hundred sixteen".