221309239 has 4 divisors (see below), whose sum is σ = 222030424. Its totient is φ = 220588056.

The previous prime is 221309233. The next prime is 221309287. The reversal of 221309239 is 932903122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221309239 - 2⁹ = 221308727 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 221309239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221309233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360132 + ... + 360745.

It is an arithmetic number, because the mean of its divisors is an integer number (55507606).

Almost surely, 2^221309239 is an apocalyptic number.

221309239 is a deficient number, since it is larger than the sum of its proper divisors (721185).

221309239 is an equidigital number, since it uses as much as digits as its factorization.

221309239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721184.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 221309239 is about 14876.4659445716. The cubic root of 221309239 is about 604.8762253906.

The spelling of 221309239 in words is "two hundred twenty-one million, three hundred nine thousand, two hundred thirty-nine".