216584815947840 has 1568 divisors, whose sum is σ = 832018742075520. Its totient is φ = 53508928831488.

The previous prime is 216584815947811. The next prime is 216584815947911. The reversal of 216584815947840 is 48749518485612.

216584815947840 is a `hidden beast` number, since 2 + 1 + 6 + 58 + 481 + 5 + 94 + 7 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

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 223 ways as a sum of consecutive naturals, for example, 81514795792 + ... + 81514798448.

Almost surely, 2^{216584815947840} is an apocalyptic number.

216584815947840 is a gapful number since it is divisible by the number (20) 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 216584815947840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (416009371037760).

216584815947840 is an abundant number, since it is smaller than the sum of its proper divisors (615433926127680).

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

216584815947840 is a wasteful number, since it uses less digits than its factorization.

216584815947840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3111 (or 3086 counting only the distinct ones).

The product of its (nonzero) digits is 619315200, while the sum is 72.

The spelling of 216584815947840 in words is "two hundred sixteen trillion, five hundred eighty-four billion, eight hundred fifteen million, nine hundred forty-seven thousand, eight hundred forty".