216666356652 has 120 divisors (see below), whose sum is σ = 572495715792. Its totient is φ = 71447184000.

The previous prime is 216666356623. The next prime is 216666356713. The reversal of 216666356652 is 256653666612.

216666356652 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

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 39 ways as a sum of consecutive naturals, for example, 56970583 + ... + 56974385.

Almost surely, 2^216666356652 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 216666356652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286247857896).

216666356652 is an abundant number, since it is smaller than the sum of its proper divisors (355829359140).

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

216666356652 is a wasteful number, since it uses less digits than its factorization.

216666356652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5661 (or 5650 counting only the distinct ones).

The product of its digits is 13996800, while the sum is 54.

The spelling of 216666356652 in words is "two hundred sixteen billion, six hundred sixty-six million, three hundred fifty-six thousand, six hundred fifty-two".