216615543524640 has 480 divisors, whose sum is σ = 838811501778096. Its totient is φ = 52314695147520.

The previous prime is 216615543524531. The next prime is 216615543524647. The reversal of 216615543524640 is 46425345516612.

216615543524640 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 1 + 5 + 54 + 3 + 524 + 64 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 31176186942096 + 185439356582544 = 5583564^2 + 13617612^2 .

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (216615543524647) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3199851 + ... + 21058730.

Almost surely, 2^{216615543524640} is an apocalyptic number.

216615543524640 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 216615543524640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (419405750889048).

216615543524640 is an abundant number, since it is smaller than the sum of its proper divisors (622195958253456).

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

216615543524640 is a wasteful number, since it uses less digits than its factorization.

216615543524640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24258674 (or 24258657 counting only the distinct ones).

The product of its (nonzero) digits is 20736000, while the sum is 54.

The spelling of 216615543524640 in words is "two hundred sixteen trillion, six hundred fifteen billion, five hundred forty-three million, five hundred twenty-four thousand, six hundred forty".