12111211210261 has 2 divisors, whose sum is σ = 12111211210262. Its totient is φ = 12111211210260.

The previous prime is 12111211210199. The next prime is 12111211210279. The reversal of 12111211210261 is 16201211211121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10320349000900 + 1790862209361 = 3212530^2 + 1338231^2 .

It is a cyclic number.

It is not a de Polignac number, because 12111211210261 - 2³³ = 12102621275669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12111211211261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6055605605130 + 6055605605131.

It is an arithmetic number, because the mean of its divisors is an integer number (6055605605131).

Almost surely, 2^{12111211210261} is an apocalyptic number.

It is an amenable number.

12111211210261 is a deficient number, since it is larger than the sum of its proper divisors (1).

12111211210261 is an equidigital number, since it uses as much as digits as its factorization.

12111211210261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 22.

Adding to 12111211210261 its reverse (16201211211121), we get a palindrome (28312422421382).

The spelling of 12111211210261 in words is "twelve trillion, one hundred eleven billion, two hundred eleven million, two hundred ten thousand, two hundred sixty-one".