1221002011111 has 2 divisors, whose sum is σ = 1221002011112. Its totient is φ = 1221002011110.

The previous prime is 1221002011093. The next prime is 1221002011127. The reversal of 1221002011111 is 1111102001221.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1111102001221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221002011111 - 2¹³ = 1221002002919 is a prime.

It is a super-2 number, since 2×1221002011111² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221002011091 and 1221002011100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221002011211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610501005555 + 610501005556.

It is an arithmetic number, because the mean of its divisors is an integer number (610501005556).

Almost surely, 2^{1221002011111} is an apocalyptic number.

1221002011111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221002011111 is an equidigital number, since it uses as much as digits as its factorization.

1221002011111 is an evil number, because the sum of its binary digits is even.

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

Adding to 1221002011111 its reverse (1111102001221), we get a palindrome (2332104012332).

The spelling of 1221002011111 in words is "one trillion, two hundred twenty-one billion, two million, eleven thousand, one hundred eleven".