221402304 has 84 divisors (see below), whose sum is σ = 644193784. Its totient is φ = 72686592.

The previous prime is 221402303. The next prime is 221402329. The reversal of 221402304 is 403204122.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (221402303) 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 11 ways as a sum of consecutive naturals, for example, 35724 + ... + 41460.

Almost surely, 2^221402304 is an apocalyptic number.

221402304 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 221402304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322096892).

221402304 is an abundant number, since it is smaller than the sum of its proper divisors (422791480).

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

221402304 is a wasteful number, since it uses less digits than its factorization.

221402304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5822 (or 5809 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 221402304 is about 14879.5935428358. The cubic root of 221402304 is about 604.9610010606.

Adding to 221402304 its reverse (403204122), we get a palindrome (624606426).

The spelling of 221402304 in words is "two hundred twenty-one million, four hundred two thousand, three hundred four".