221308704 has 144 divisors (see below), whose sum is σ = 651006720. Its totient is φ = 71285760.

The previous prime is 221308679. The next prime is 221308709. The reversal of 221308704 is 407803122.

221308704 is digitally balanced in base 3, 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 (144).

It is not an unprimeable number, because it can be changed into a prime (221308709) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1615324 + ... + 1615460.

It is an arithmetic number, because the mean of its divisors is an integer number (4520880).

Almost surely, 2^221308704 is an apocalyptic number.

221308704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221308704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (325503360).

221308704 is an abundant number, since it is smaller than the sum of its proper divisors (429698016).

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

221308704 is a wasteful number, since it uses less digits than its factorization.

221308704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 221308704 is about 14876.4479631396. The cubic root of 221308704 is about 604.8757379746.

The spelling of 221308704 in words is "two hundred twenty-one million, three hundred eight thousand, seven hundred four".