1111001221221 has 64 divisors (see below), whose sum is σ = 1638421862400. Its totient is φ = 666743463936.

The previous prime is 1111001221159. The next prime is 1111001221223. The reversal of 1111001221221 is 1221221001111.

It is a happy number.

It is not a de Polignac number, because 1111001221221 - 2⁶ = 1111001221157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1111001221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111001221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 29035020 + ... + 29073258.

It is an arithmetic number, because the mean of its divisors is an integer number (25600341600).

Almost surely, 2^{1111001221221} is an apocalyptic number.

It is an amenable number.

1111001221221 is a deficient number, since it is larger than the sum of its proper divisors (527420641179).

1111001221221 is a wasteful number, since it uses less digits than its factorization.

1111001221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38558.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1111001221221 its reverse (1221221001111), we get a palindrome (2332222222332).

The spelling of 1111001221221 in words is "one trillion, one hundred eleven billion, one million, two hundred twenty-one thousand, two hundred twenty-one".