1221221011110 has 32 divisors (see below), whose sum is σ = 2986231004640. Its totient is φ = 319514427648.

The previous prime is 1221221011099. The next prime is 1221221011117. The reversal of 1221221011110 is 111101221221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221221011110.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221221011117) 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, 384030175 + ... + 384033354.

It is an arithmetic number, because the mean of its divisors is an integer number (93319718895).

Almost surely, 2^{1221221011110} is an apocalyptic number.

1221221011110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221221011110 is an abundant number, since it is smaller than the sum of its proper divisors (1765009993530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221221011110 is a wasteful number, since it uses less digits than its factorization.

1221221011110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768063592.

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

Adding to 1221221011110 its reverse (111101221221), we get a palindrome (1332322232331).

The spelling of 1221221011110 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, eleven thousand, one hundred ten".