12661465261 has 2 divisors, whose sum is σ = 12661465262. Its totient is φ = 12661465260.

The previous prime is 12661465259. The next prime is 12661465301. The reversal of 12661465261 is 16256416621.

It is an a-pointer prime, because the next prime (12661465301) can be obtained adding 12661465261 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12408846025 + 252619236 = 111395^2 + 15894^2 .

It is an emirp because it is prime and its reverse (16256416621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12661465261 - 2¹ = 12661465259 is a prime.

Together with 12661465259, 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 (12661465361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6330732630 + 6330732631.

It is an arithmetic number, because the mean of its divisors is an integer number (6330732631).

Almost surely, 2^12661465261 is an apocalyptic number.

It is an amenable number.

12661465261 is a deficient number, since it is larger than the sum of its proper divisors (1).

12661465261 is an equidigital number, since it uses as much as digits as its factorization.

12661465261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 40.

The spelling of 12661465261 in words is "twelve billion, six hundred sixty-one million, four hundred sixty-five thousand, two hundred sixty-one".