1261275842117 has 2 divisors, whose sum is σ = 1261275842118. Its totient is φ = 1261275842116.

The previous prime is 1261275842111. The next prime is 1261275842119. The reversal of 1261275842117 is 7112485721621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 807897166561 + 453378675556 = 898831^2 + 673334^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261275842117 - 2¹² = 1261275838021 is a prime.

It is a super-2 number, since 2×1261275842117² (a number of 25 digits) contains 22 as substring.

Together with 1261275842119, 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 (1261275842111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630637921058 + 630637921059.

It is an arithmetic number, because the mean of its divisors is an integer number (630637921059).

Almost surely, 2^{1261275842117} is an apocalyptic number.

It is an amenable number.

1261275842117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261275842117 is an equidigital number, since it uses as much as digits as its factorization.

1261275842117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 376320, while the sum is 47.

The spelling of 1261275842117 in words is "one trillion, two hundred sixty-one billion, two hundred seventy-five million, eight hundred forty-two thousand, one hundred seventeen".