1216313766720 has 504 divisors, whose sum is σ = 4537252114200. Its totient is φ = 298933420032.

The previous prime is 1216313766697. The next prime is 1216313766737. The reversal of 1216313766720 is 276673136121.

1216313766720 is a `hidden beast` number, since 1 + 2 + 1 + 631 + 3 + 7 + 6 + 6 + 7 + 2 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 175815844416 + 1040497922304 = 419304^2 + 1020048^2 .

It is a super-2 number, since 2×1216313766720² (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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 393754936 + ... + 393758024.

Almost surely, 2^{1216313766720} is an apocalyptic number.

1216313766720 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 1216313766720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2268626057100).

1216313766720 is an abundant number, since it is smaller than the sum of its proper divisors (3320938347480).

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

1216313766720 is a wasteful number, since it uses less digits than its factorization.

1216313766720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3947 (or 3921 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The spelling of 1216313766720 in words is "one trillion, two hundred sixteen billion, three hundred thirteen million, seven hundred sixty-six thousand, seven hundred twenty".