1221131041225 has 24 divisors (see below), whose sum is σ = 1542881439000. Its totient is φ = 958404894720.

The previous prime is 1221131041211. The next prime is 1221131041271. The reversal of 1221131041225 is 5221401311221.

It can be written as a sum of positive squares in 12 ways, for example, as 906144071056 + 314986970169 = 951916^2 + 561237^2 .

It is not a de Polignac number, because 1221131041225 - 2³⁹ = 671375227337 is a prime.

It is a super-2 number, since 2×1221131041225² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 1221131041225.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27470217 + ... + 27514633.

It is an arithmetic number, because the mean of its divisors is an integer number (64286726625).

Almost surely, 2^{1221131041225} is an apocalyptic number.

It is an amenable number.

1221131041225 is a deficient number, since it is larger than the sum of its proper divisors (321750397775).

1221131041225 is a wasteful number, since it uses less digits than its factorization.

1221131041225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65229 (or 65224 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

Adding to 1221131041225 its reverse (5221401311221), we get a palindrome (6442532352446).

The spelling of 1221131041225 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-one million, forty-one thousand, two hundred twenty-five".