223131209 has 4 divisors (see below), whose sum is σ = 255007104. Its totient is φ = 191255316.

The previous prime is 223131187. The next prime is 223131247. The reversal of 223131209 is 902131322.

223131209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 902131322 = 2 ⋅451065661.

It is not a de Polignac number, because 223131209 - 2⁸ = 223130953 is a prime.

It is a super-3 number, since 3×223131209³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (223131109) 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, 15937937 + ... + 15937950.

It is an arithmetic number, because the mean of its divisors is an integer number (63751776).

Almost surely, 2^223131209 is an apocalyptic number.

It is an amenable number.

223131209 is a deficient number, since it is larger than the sum of its proper divisors (31875895).

223131209 is an equidigital number, since it uses as much as digits as its factorization.

223131209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31875894.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 223131209 is about 14937.5770792990. The cubic root of 223131209 is about 606.5316100692.

The spelling of 223131209 in words is "two hundred twenty-three million, one hundred thirty-one thousand, two hundred nine".