1216358894520 has 768 divisors, whose sum is σ = 5011619558400. Its totient is φ = 248523448320.

The previous prime is 1216358894453. The next prime is 1216358894539. The reversal of 1216358894520 is 254988536121.

1216358894520 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 3 + 588 + 9 + 4 + 52 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 536075946 + ... + 536078214.

It is an arithmetic number, because the mean of its divisors is an integer number (6525546300).

Almost surely, 2^{1216358894520} is an apocalyptic number.

1216358894520 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 1216358894520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2505809779200).

1216358894520 is an abundant number, since it is smaller than the sum of its proper divisors (3795260663880).

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

1216358894520 is a wasteful number, since it uses less digits than its factorization.

1216358894520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2620 (or 2613 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 54.

The spelling of 1216358894520 in words is "one trillion, two hundred sixteen billion, three hundred fifty-eight million, eight hundred ninety-four thousand, five hundred twenty".