1211220233 has 4 divisors (see below), whose sum is σ = 1282468500. Its totient is φ = 1139971968.

The previous prime is 1211220223. The next prime is 1211220239. The reversal of 1211220233 is 3320221121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3320221121 = 7 ⋅474317303.

It can be written as a sum of positive squares in 2 ways, for example, as 531210304 + 680009929 = 23048^2 + 26077^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211220233 - 2⁴ = 1211220217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 71248249 = 1211220233 / (1 + 2 + 1 + 1 + 2 + 2 + 0 + 2 + 3 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211220239) 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, 35624108 + ... + 35624141.

It is an arithmetic number, because the mean of its divisors is an integer number (320617125).

Almost surely, 2^1211220233 is an apocalyptic number.

It is an amenable number.

1211220233 is a deficient number, since it is larger than the sum of its proper divisors (71248267).

1211220233 is an equidigital number, since it uses as much as digits as its factorization.

1211220233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71248266.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1211220233 is about 34802.5894582573. The cubic root of 1211220233 is about 1065.9603211098.

Adding to 1211220233 its reverse (3320221121), we get a palindrome (4531441354).

The spelling of 1211220233 in words is "one billion, two hundred eleven million, two hundred twenty thousand, two hundred thirty-three".