221390208 has 96 divisors (see below), whose sum is σ = 686125440. Its totient is φ = 68115456.

The previous prime is 221390207. The next prime is 221390231. The reversal of 221390208 is 802093122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221390207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7585 + ... + 22367.

It is an arithmetic number, because the mean of its divisors is an integer number (7147140).

Almost surely, 2^221390208 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 221390208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343062720).

221390208 is an abundant number, since it is smaller than the sum of its proper divisors (464735232).

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

221390208 is a wasteful number, since it uses less digits than its factorization.

221390208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14816 (or 14801 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 221390208 is about 14879.1870745683. The cubic root of 221390208 is about 604.9499837986.

The spelling of 221390208 in words is "two hundred twenty-one million, three hundred ninety thousand, two hundred eight".