1221121225 has 12 divisors (see below), whose sum is σ = 1515458560. Its totient is φ = 976078800.

The previous prime is 1221121199. The next prime is 1221121259. The reversal of 1221121225 is 5221211221.

It is a happy number.

It is not a de Polignac number, because 1221121225 - 2⁵ = 1221121193 is a prime.

It is a super-2 number, since 2×1221121225² = 2982274092291001250, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10936 + ... + 50614.

Almost surely, 2^1221121225 is an apocalyptic number.

It is an amenable number.

1221121225 is a deficient number, since it is larger than the sum of its proper divisors (294337335).

1221121225 is a wasteful number, since it uses less digits than its factorization.

1221121225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40920 (or 40915 counting only the distinct ones).

The product of its digits is 160, while the sum is 19.

The square root of 1221121225 is about 34944.5449963224. The cubic root of 1221121225 is about 1068.8569693327.

Adding to 1221121225 its reverse (5221211221), we get a palindrome (6442332446).

The spelling of 1221121225 in words is "one billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-five".