1211561223 has 4 divisors (see below), whose sum is σ = 1615414968. Its totient is φ = 807707480.

The previous prime is 1211561213. The next prime is 1211561243. The reversal of 1211561223 is 3221651121.

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 1211561223 - 2⁴ = 1211561207 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211561193 and 1211561202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211561213) 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, 201926868 + ... + 201926873.

It is an arithmetic number, because the mean of its divisors is an integer number (403853742).

Almost surely, 2^1211561223 is an apocalyptic number.

1211561223 is a deficient number, since it is larger than the sum of its proper divisors (403853745).

1211561223 is an equidigital number, since it uses as much as digits as its factorization.

1211561223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403853744.

The product of its digits is 720, while the sum is 24.

The square root of 1211561223 is about 34807.4880305948. The cubic root of 1211561223 is about 1066.0603435762.

The spelling of 1211561223 in words is "one billion, two hundred eleven million, five hundred sixty-one thousand, two hundred twenty-three".