261646243624613 has 2 divisors, whose sum is σ = 261646243624614. Its totient is φ = 261646243624612.

The previous prime is 261646243624583. The next prime is 261646243624669. The reversal of 261646243624613 is 316426342646162.

It is an a-pointer prime, because the next prime (261646243624669) can be obtained adding 261646243624613 to its sum of digits (56).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 218824624169284 + 42821619455329 = 14792722^2 + 6543823^2 .

It is a cyclic number.

It is not a de Polignac number, because 261646243624613 - 2³² = 261641948657317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261646243621613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130823121812306 + 130823121812307.

It is an arithmetic number, because the mean of its divisors is an integer number (130823121812307).

Almost surely, 2^{261646243624613} is an apocalyptic number.

It is an amenable number.

261646243624613 is a deficient number, since it is larger than the sum of its proper divisors (1).

261646243624613 is an equidigital number, since it uses as much as digits as its factorization.

261646243624613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35831808, while the sum is 56.

The spelling of 261646243624613 in words is "two hundred sixty-one trillion, six hundred forty-six billion, two hundred forty-three million, six hundred twenty-four thousand, six hundred thirteen".