221206668 has 12 divisors (see below), whose sum is σ = 516148920. Its totient is φ = 73735552.

The previous prime is 221206651. The next prime is 221206673. The reversal of 221206668 is 866602122.

221206668 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9216933 + ... + 9216956.

It is an arithmetic number, because the mean of its divisors is an integer number (43012410).

Almost surely, 2^221206668 is an apocalyptic number.

It is an amenable number.

221206668 is an abundant number, since it is smaller than the sum of its proper divisors (294942252).

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

221206668 is a wasteful number, since it uses less digits than its factorization.

221206668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18433896 (or 18433894 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 221206668 is about 14873.0181200723. The cubic root of 221206668 is about 604.7827628867.

The spelling of 221206668 in words is "two hundred twenty-one million, two hundred six thousand, six hundred sixty-eight".