121220011111 has 2 divisors, whose sum is σ = 121220011112. Its totient is φ = 121220011110.

The previous prime is 121220011091. The next prime is 121220011127. The reversal of 121220011111 is 111110022121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121220011111 - 2¹⁷ = 121219880039 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121220011091 and 121220011100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121220011151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610005555 + 60610005556.

It is an arithmetic number, because the mean of its divisors is an integer number (60610005556).

Almost surely, 2^121220011111 is an apocalyptic number.

121220011111 is a deficient number, since it is larger than the sum of its proper divisors (1).

121220011111 is an equidigital number, since it uses as much as digits as its factorization.

121220011111 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 121220011111 its reverse (111110022121), we get a palindrome (232330033232).

The spelling of 121220011111 in words is "one hundred twenty-one billion, two hundred twenty million, eleven thousand, one hundred eleven".