221430289 has 4 divisors (see below), whose sum is σ = 221461300. Its totient is φ = 221399280.

The previous prime is 221430281. The next prime is 221430329. The reversal of 221430289 is 982034122.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 25654225 + 195776064 = 5065^2 + 13992^2 .

It is a cyclic number.

It is not a de Polignac number, because 221430289 - 2³ = 221430281 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221430289.

It is not an unprimeable number, because it can be changed into a prime (221430281) 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 3 ways as a sum of consecutive naturals, for example, 1219 + ... + 21079.

It is an arithmetic number, because the mean of its divisors is an integer number (55365325).

Almost surely, 2^221430289 is an apocalyptic number.

It is an amenable number.

221430289 is a deficient number, since it is larger than the sum of its proper divisors (31011).

221430289 is a wasteful number, since it uses less digits than its factorization.

221430289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31010.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 221430289 is about 14880.5338949918. The cubic root of 221430289 is about 604.9864887814.

The spelling of 221430289 in words is "two hundred twenty-one million, four hundred thirty thousand, two hundred eighty-nine".