1221100233 has 16 divisors (see below), whose sum is σ = 1692296256. Its totient is φ = 782516160.

The previous prime is 1221100229. The next prime is 1221100241. The reversal of 1221100233 is 3320011221.

It is not a de Polignac number, because 1221100233 - 2² = 1221100229 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221100213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57058 + ... + 75483.

It is an arithmetic number, because the mean of its divisors is an integer number (105768516).

Almost surely, 2^1221100233 is an apocalyptic number.

It is an amenable number.

1221100233 is a deficient number, since it is larger than the sum of its proper divisors (471196023).

1221100233 is a wasteful number, since it uses less digits than its factorization.

1221100233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132664.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1221100233 is about 34944.2446334157. The cubic root of 1221100233 is about 1068.8508444770.

Adding to 1221100233 its reverse (3320011221), we get a palindrome (4541111454).

The spelling of 1221100233 in words is "one billion, two hundred twenty-one million, one hundred thousand, two hundred thirty-three".