1212233221 has 4 divisors (see below), whose sum is σ = 1212549772. Its totient is φ = 1211916672.

The previous prime is 1212233219. The next prime is 1212233233. The reversal of 1212233221 is 1223322121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 320016321 + 892216900 = 17889^2 + 29870^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212233221 - 2¹ = 1212233219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212233251) 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, 152460 + ... + 160213.

It is an arithmetic number, because the mean of its divisors is an integer number (303137443).

Almost surely, 2^1212233221 is an apocalyptic number.

It is an amenable number.

1212233221 is a deficient number, since it is larger than the sum of its proper divisors (316551).

1212233221 is an equidigital number, since it uses as much as digits as its factorization.

1212233221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316550.

The product of its digits is 288, while the sum is 19.

The square root of 1212233221 is about 34817.1397590325. The cubic root of 1212233221 is about 1066.2574055698.

Adding to 1212233221 its reverse (1223322121), we get a palindrome (2435555342).

Subtracting 1212233221 from its reverse (1223322121), we obtain a square (11088900 = 3330²).

The spelling of 1212233221 in words is "one billion, two hundred twelve million, two hundred thirty-three thousand, two hundred twenty-one".