1210111221221 has 16 divisors (see below), whose sum is σ = 1467013378176. Its totient is φ = 974439438336.

The previous prime is 1210111221191. The next prime is 1210111221223. The reversal of 1210111221221 is 1221221110121.

It is not a de Polignac number, because 1210111221221 - 2⁶ = 1210111221157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1210111221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210111221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9230156 + ... + 9360341.

It is an arithmetic number, because the mean of its divisors is an integer number (91688336136).

Almost surely, 2^{1210111221221} is an apocalyptic number.

It is an amenable number.

1210111221221 is a deficient number, since it is larger than the sum of its proper divisors (256902156955).

1210111221221 is a wasteful number, since it uses less digits than its factorization.

1210111221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18591068.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1210111221221 its reverse (1221221110121), we get a palindrome (2431332331342).

The spelling of 1210111221221 in words is "one trillion, two hundred ten billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".