216828991201 has 3 divisors (see below), whose sum is σ = 216829456851. Its totient is φ = 216828525552.

The previous prime is 216828991193. The next prime is 216828991207. The reversal of 216828991201 is 102199828612.

The square root of 216828991201 is 465649.

It is a perfect power (a square), and thus also a powerful number.

216828991201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 210819640801 + 6009350400 = 459151^2 + 77520^2 .

It is not a de Polignac number, because 216828991201 - 2³ = 216828991193 is a prime.

It is a super-2 number, since 2×216828991201² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216828991207) by changing a digit.

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 2 ways as a sum of consecutive naturals, for example, 232825 + ... + 698473.

It is an arithmetic number, because the mean of its divisors is an integer number (72276485617).

Almost surely, 2^216828991201 is an apocalyptic number.

216828991201 is the 465649-th square number.

216828991201 is the 232825-th centered octagonal number.

It is an amenable number.

216828991201 is a deficient number, since it is larger than the sum of its proper divisors (465650).

216828991201 is an frugal number, since it uses more digits than its factorization.

216828991201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931298 (or 465649 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 49.

Multiplying 216828991201 by its sum of digits (49), we get a square (10624620568849 = 3259543²).

The spelling of 216828991201 in words is "two hundred sixteen billion, eight hundred twenty-eight million, nine hundred ninety-one thousand, two hundred one".