221909239 has 8 divisors (see below), whose sum is σ = 228373920. Its totient is φ = 215469216.

The previous prime is 221909213. The next prime is 221909243. The reversal of 221909239 is 932909122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221909239 - 2⁹ = 221908727 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221909198 and 221909207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221909209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12942 + ... + 24724.

It is an arithmetic number, because the mean of its divisors is an integer number (28546740).

Almost surely, 2^221909239 is an apocalyptic number.

221909239 is a deficient number, since it is larger than the sum of its proper divisors (6464681).

221909239 is a wasteful number, since it uses less digits than its factorization.

221909239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12329.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 221909239 is about 14896.6183746513. The cubic root of 221909239 is about 605.4223665419.

The spelling of 221909239 in words is "two hundred twenty-one million, nine hundred nine thousand, two hundred thirty-nine".