1221021100111 has 8 divisors (see below), whose sum is σ = 1222295114880. Its totient is φ = 1219747235928.

The previous prime is 1221021100073. The next prime is 1221021100133. The reversal of 1221021100111 is 1110011201221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221021100111 - 2³¹ = 1218873616463 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221021100091 and 1221021100100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221021100811) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 24111760 + ... + 24162346.

It is an arithmetic number, because the mean of its divisors is an integer number (152786889360).

Almost surely, 2^{1221021100111} is an apocalyptic number.

1221021100111 is a deficient number, since it is larger than the sum of its proper divisors (1274014769).

1221021100111 is a wasteful number, since it uses less digits than its factorization.

1221021100111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75293.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1221021100111 its reverse (1110011201221), we get a palindrome (2331032301332).

The spelling of 1221021100111 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred thousand, one hundred eleven".