1211530223 has 4 divisors (see below), whose sum is σ = 1211974968. Its totient is φ = 1211085480.

The previous prime is 1211530219. The next prime is 1211530253. The reversal of 1211530223 is 3220351121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3220351121 = 13 ⋅247719317.

It is a cyclic number.

It is not a de Polignac number, because 1211530223 - 2² = 1211530219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211530195 and 1211530204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211530253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218261 + ... + 223742.

It is an arithmetic number, because the mean of its divisors is an integer number (302993742).

Almost surely, 2^1211530223 is an apocalyptic number.

1211530223 is a deficient number, since it is larger than the sum of its proper divisors (444745).

1211530223 is an equidigital number, since it uses as much as digits as its factorization.

1211530223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444744.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1211530223 is about 34807.0427212655. The cubic root of 1211530223 is about 1066.0512511337.

Adding to 1211530223 its reverse (3220351121), we get a palindrome (4431881344).

The spelling of 1211530223 in words is "one billion, two hundred eleven million, five hundred thirty thousand, two hundred twenty-three".