1312240403261 has 2 divisors, whose sum is σ = 1312240403262. Its totient is φ = 1312240403260.

The previous prime is 1312240403237. The next prime is 1312240403263. The reversal of 1312240403261 is 1623040422131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 720833262361 + 591407140900 = 849019^2 + 769030^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312240403261 - 2²² = 1312236208957 is a prime.

Together with 1312240403263, 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 (1312240403263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656120201630 + 656120201631.

It is an arithmetic number, because the mean of its divisors is an integer number (656120201631).

Almost surely, 2^{1312240403261} is an apocalyptic number.

It is an amenable number.

1312240403261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312240403261 is an equidigital number, since it uses as much as digits as its factorization.

1312240403261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 29.

Adding to 1312240403261 its reverse (1623040422131), we get a palindrome (2935280825392).

The spelling of 1312240403261 in words is "one trillion, three hundred twelve billion, two hundred forty million, four hundred three thousand, two hundred sixty-one".