1221313012111 has 4 divisors (see below), whose sum is σ = 1221382316232. Its totient is φ = 1221243707992.

The previous prime is 1221313012063. The next prime is 1221313012159. The reversal of 1221313012111 is 1112103131221.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1221313012063) and next prime (1221313012159).

It is a cyclic number.

It is not a de Polignac number, because 1221313012111 - 2⁹ = 1221313011599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221313012211) 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 3 ways as a sum of consecutive naturals, for example, 34625620 + ... + 34660873.

It is an arithmetic number, because the mean of its divisors is an integer number (305345579058).

Almost surely, 2^{1221313012111} is an apocalyptic number.

1221313012111 is a deficient number, since it is larger than the sum of its proper divisors (69304121).

1221313012111 is an equidigital number, since it uses as much as digits as its factorization.

1221313012111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69304120.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1221313012111 its reverse (1112103131221), we get a palindrome (2333416143332).

The spelling of 1221313012111 in words is "one trillion, two hundred twenty-one billion, three hundred thirteen million, twelve thousand, one hundred eleven".