1211203031123 has 2 divisors, whose sum is σ = 1211203031124. Its totient is φ = 1211203031122.

The previous prime is 1211203031111. The next prime is 1211203031153. The reversal of 1211203031123 is 3211303021121.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211203031123 - 2⁸ = 1211203030867 is a prime.

It is a super-2 number, since 2×1211203031123² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211203031095 and 1211203031104.

It is not a weakly prime, because it can be changed into another prime (1211203031153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605601515561 + 605601515562.

It is an arithmetic number, because the mean of its divisors is an integer number (605601515562).

Almost surely, 2^{1211203031123} is an apocalyptic number.

1211203031123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211203031123 is an equidigital number, since it uses as much as digits as its factorization.

1211203031123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 1211203031123 its reverse (3211303021121), we get a palindrome (4422506052244).

The spelling of 1211203031123 in words is "one trillion, two hundred eleven billion, two hundred three million, thirty-one thousand, one hundred twenty-three".