221021768 has 32 divisors (see below), whose sum is σ = 456334560. Its totient is φ = 99521280.

The previous prime is 221021761. The next prime is 221021771. The reversal of 221021768 is 867120122.

221021768 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221021768.

It is not an unprimeable number, because it can be changed into a prime (221021761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2321 + ... + 21152.

It is an arithmetic number, because the mean of its divisors is an integer number (14260455).

Almost surely, 2^221021768 is an apocalyptic number.

It is an amenable number.

221021768 is an abundant number, since it is smaller than the sum of its proper divisors (235312792).

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

221021768 is a wasteful number, since it uses less digits than its factorization.

221021768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23597 (or 23593 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 221021768 is about 14866.8008663599. The cubic root of 221021768 is about 604.6142093417.

The spelling of 221021768 in words is "two hundred twenty-one million, twenty-one thousand, seven hundred sixty-eight".