1305631031261 has 2 divisors, whose sum is σ = 1305631031262. Its totient is φ = 1305631031260.

The previous prime is 1305631031231. The next prime is 1305631031291. The reversal of 1305631031261 is 1621301365031.

It is a balanced prime because it is at equal distance from previous prime (1305631031231) and next prime (1305631031291).

It can be written as a sum of positive squares in only one way, i.e., 1126591188100 + 179039843161 = 1061410^2 + 423131^2 .

It is a cyclic number.

It is not a de Polignac number, because 1305631031261 - 2⁶ = 1305631031197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1305631031231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 652815515630 + 652815515631.

It is an arithmetic number, because the mean of its divisors is an integer number (652815515631).

Almost surely, 2^{1305631031261} is an apocalyptic number.

It is an amenable number.

1305631031261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1305631031261 is an equidigital number, since it uses as much as digits as its factorization.

1305631031261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 32.

Adding to 1305631031261 its reverse (1621301365031), we get a palindrome (2926932396292).

The spelling of 1305631031261 in words is "one trillion, three hundred five billion, six hundred thirty-one million, thirty-one thousand, two hundred sixty-one".