1221355233 has 24 divisors (see below), whose sum is σ = 2104832160. Its totient is φ = 697916520.

The previous prime is 1221355231. The next prime is 1221355243. The reversal of 1221355233 is 3325531221.

It is a happy number.

1221355233 is a `hidden beast` number, since 1 + 2 + 2 + 135 + 523 + 3 = 666.

It is not a de Polignac number, because 1221355233 - 2¹ = 1221355231 is a prime.

It is a super-3 number, since 3×1221355233³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 1221355197 and 1221355206.

It is not an unprimeable number, because it can be changed into a prime (1221355231) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 460263 + ... + 462908.

It is an arithmetic number, because the mean of its divisors is an integer number (87701340).

Almost surely, 2^1221355233 is an apocalyptic number.

It is an amenable number.

1221355233 is a deficient number, since it is larger than the sum of its proper divisors (883476927).

1221355233 is an equidigital number, since it uses as much as digits as its factorization.

1221355233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923194 (or 923181 counting only the distinct ones).

The product of its digits is 5400, while the sum is 27.

The square root of 1221355233 is about 34947.8931124610. The cubic root of 1221355233 is about 1068.9252413167.

Adding to 1221355233 its reverse (3325531221), we get a palindrome (4546886454).

The spelling of 1221355233 in words is "one billion, two hundred twenty-one million, three hundred fifty-five thousand, two hundred thirty-three".