1211243123 has 2 divisors, whose sum is σ = 1211243124. Its totient is φ = 1211243122.

The previous prime is 1211243119. The next prime is 1211243213. The reversal of 1211243123 is 3213421121.

Together with next prime (1211243213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211243123 - 2² = 1211243119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211243095 and 1211243104.

It is not a weakly prime, because it can be changed into another prime (1211233123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605621561 + 605621562.

It is an arithmetic number, because the mean of its divisors is an integer number (605621562).

Almost surely, 2^1211243123 is an apocalyptic number.

1211243123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211243123 is an equidigital number, since it uses as much as digits as its factorization.

1211243123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 20.

The square root of 1211243123 is about 34802.9183115439. The cubic root of 1211243123 is about 1065.9670360125.

Adding to 1211243123 its reverse (3213421121), we get a palindrome (4424664244).

The spelling of 1211243123 in words is "one billion, two hundred eleven million, two hundred forty-three thousand, one hundred twenty-three".