261683997013 has 2 divisors, whose sum is σ = 261683997014. Its totient is φ = 261683997012.

The previous prime is 261683997011. The next prime is 261683997041. The reversal of 261683997013 is 310799386162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 261241609924 + 442387089 = 511118^2 + 21033^2 .

It is a cyclic number.

It is not a de Polignac number, because 261683997013 - 2¹ = 261683997011 is a prime.

Together with 261683997011, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261683997011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130841998506 + 130841998507.

It is an arithmetic number, because the mean of its divisors is an integer number (130841998507).

Almost surely, 2^261683997013 is an apocalyptic number.

It is an amenable number.

261683997013 is a deficient number, since it is larger than the sum of its proper divisors (1).

261683997013 is an equidigital number, since it uses as much as digits as its factorization.

261683997013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2939328, while the sum is 55.

The spelling of 261683997013 in words is "two hundred sixty-one billion, six hundred eighty-three million, nine hundred ninety-seven thousand, thirteen".