1011221111 has 2 divisors, whose sum is σ = 1011221112.
Its totient is φ = 1011221110.
The previous prime is 1011221083. The next prime is 1011221129. The reversal of 1011221111 is 1111221101.
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 1011221111 - 218 = 1010958967 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 1011221092 and 1011221101.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (1011221161) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505610555 + 505610556.
It is an arithmetic number, because the mean of its divisors is an integer number (505610556).
Almost surely, 21011221111 is an apocalyptic number.
1011221111 is a deficient number, since it is larger than the sum of its proper divisors (1).
1011221111 is an equidigital number, since it uses as much as digits as its factorization.
1011221111 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 4, while the sum is 11.
The square root of 1011221111 is about 31799.7030017577.
The cubic root of 1011221111 is about 1003.7264665313.
Adding to 1011221111 its reverse (1111221101), we get a palindrome (2122442212).
The spelling of 1011221111 in words is "one billion, eleven million, two hundred twenty-one thousand, one hundred eleven".