221379288 has 128 divisors (see below), whose sum is σ = 621035520. Its totient is φ = 65318400.

The previous prime is 221379281. The next prime is 221379293. The reversal of 221379288 is 882973122.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221379281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1466013 + ... + 1466163.

It is an arithmetic number, because the mean of its divisors is an integer number (4851840).

Almost surely, 2^221379288 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 221379288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (310517760).

221379288 is an abundant number, since it is smaller than the sum of its proper divisors (399656232).

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

221379288 is a wasteful number, since it uses less digits than its factorization.

221379288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337 (or 333 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 221379288 is about 14878.8201145118. The cubic root of 221379288 is about 604.9400373147.

The spelling of 221379288 in words is "two hundred twenty-one million, three hundred seventy-nine thousand, two hundred eighty-eight".