1216646507520 has 1056 divisors, whose sum is σ = 4590268784640. Its totient is φ = 305539153920.

The previous prime is 1216646507507. The next prime is 1216646507579. The reversal of 1216646507520 is 257056466121.

1216646507520 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 64 + 65 + 0 + 7 + 520 = 666.

It is a super-2 number, since 2×1216646507520² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9287377855 + ... + 9287377985.

It is an arithmetic number, because the mean of its divisors is an integer number (4346845440).

Almost surely, 2^{1216646507520} is an apocalyptic number.

1216646507520 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 1216646507520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2295134392320).

1216646507520 is an abundant number, since it is smaller than the sum of its proper divisors (3373622277120).

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

1216646507520 is a wasteful number, since it uses less digits than its factorization.

1216646507520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 1216646507520 in words is "one trillion, two hundred sixteen billion, six hundred forty-six million, five hundred seven thousand, five hundred twenty".