216780506172 has 96 divisors (see below), whose sum is σ = 582756249600. Its totient is φ = 69606129600.

The previous prime is 216780506149. The next prime is 216780506191. The reversal of 216780506172 is 271605087612.

216780506172 is a `hidden beast` number, since 2 + 1 + 6 + 78 + 0 + 506 + 1 + 72 = 666.

216780506172 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1269597 + ... + 1430187.

It is an arithmetic number, because the mean of its divisors is an integer number (6070377600).

Almost surely, 2^216780506172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216780506172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (291378124800).

216780506172 is an abundant number, since it is smaller than the sum of its proper divisors (365975743428).

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

216780506172 is a wasteful number, since it uses less digits than its factorization.

216780506172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161064 (or 161056 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 216780506172 in words is "two hundred sixteen billion, seven hundred eighty million, five hundred six thousand, one hundred seventy-two".