1221155033 has 16 divisors (see below), whose sum is σ = 1505589120. Its totient is φ = 966541056.

The previous prime is 1221155021. The next prime is 1221155041. The reversal of 1221155033 is 3305511221.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1221155033 - 2⁴ = 1221155017 is a prime.

It is a super-2 number, since 2×1221155033² = 2982439229242462178, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221155083) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90503 + ... + 103116.

It is an arithmetic number, because the mean of its divisors is an integer number (94099320).

Almost surely, 2^1221155033 is an apocalyptic number.

It is an amenable number.

1221155033 is a deficient number, since it is larger than the sum of its proper divisors (284434087).

1221155033 is a wasteful number, since it uses less digits than its factorization.

1221155033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193696.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 1221155033 is about 34945.0287308510. The cubic root of 1221155033 is about 1068.8668333774.

Adding to 1221155033 its reverse (3305511221), we get a palindrome (4526666254).

The spelling of 1221155033 in words is "one billion, two hundred twenty-one million, one hundred fifty-five thousand, thirty-three".