1111122121 has 2 divisors, whose sum is σ = 1111122122. Its totient is φ = 1111122120.

The previous prime is 1111122101. The next prime is 1111122139. The reversal of 1111122121 is 1212211111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 647193600 + 463928521 = 25440^2 + 21539^2 .

It is an emirp because it is prime and its reverse (1212211111) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1111122121 is a prime.

It is not a weakly prime, because it can be changed into another prime (1111122101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555561060 + 555561061.

It is an arithmetic number, because the mean of its divisors is an integer number (555561061).

Almost surely, 2^1111122121 is an apocalyptic number.

It is an amenable number.

1111122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111122121 is an equidigital number, since it uses as much as digits as its factorization.

1111122121 is an evil number, because the sum of its binary digits is even.

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

The square root of 1111122121 is about 33333.4984812576. The cubic root of 1111122121 is about 1035.7475896685.

Adding to 1111122121 its reverse (1212211111), we get a palindrome (2323333232).

The spelling of 1111122121 in words is "one billion, one hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".