221223309 has 4 divisors (see below), whose sum is σ = 294964416. Its totient is φ = 147482204.

The previous prime is 221223307. The next prime is 221223311. The reversal of 221223309 is 903322122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (221223307) and next prime (221223311).

It is a cyclic number.

It is not a de Polignac number, because 221223309 - 2¹ = 221223307 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221223307) 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, 36870549 + ... + 36870554.

It is an arithmetic number, because the mean of its divisors is an integer number (73741104).

Almost surely, 2^221223309 is an apocalyptic number.

It is an amenable number.

221223309 is a deficient number, since it is larger than the sum of its proper divisors (73741107).

221223309 is an equidigital number, since it uses as much as digits as its factorization.

221223309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73741106.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 221223309 is about 14873.5775454327. The cubic root of 221223309 is about 604.7979280980.

The spelling of 221223309 in words is "two hundred twenty-one million, two hundred twenty-three thousand, three hundred nine".