1211112101 has 2 divisors, whose sum is σ = 1211112102. Its totient is φ = 1211112100.

The previous prime is 1211112059. The next prime is 1211112103. The reversal of 1211112101 is 1012111121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1211109601 + 2500 = 34801^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211112101 - 2¹⁸ = 1210849957 is a prime.

Together with 1211112103, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211112103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605556050 + 605556051.

It is an arithmetic number, because the mean of its divisors is an integer number (605556051).

Almost surely, 2^1211112101 is an apocalyptic number.

It is an amenable number.

1211112101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211112101 is an equidigital number, since it uses as much as digits as its factorization.

1211112101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 1211112101 is about 34801.0359184896. The cubic root of 1211112101 is about 1065.9285988712.

Adding to 1211112101 its reverse (1012111121), we get a palindrome (2223223222).

The spelling of 1211112101 in words is "one billion, two hundred eleven million, one hundred twelve thousand, one hundred one".