21248426840261 has 2 divisors, whose sum is σ = 21248426840262. Its totient is φ = 21248426840260.

The previous prime is 21248426840159. The next prime is 21248426840297. The reversal of 21248426840261 is 16204862484212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16412302464100 + 4836124376161 = 4051210^2 + 2199119^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21248426840261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21248426840761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10624213420130 + 10624213420131.

It is an arithmetic number, because the mean of its divisors is an integer number (10624213420131).

Almost surely, 2^{21248426840261} is an apocalyptic number.

It is an amenable number.

21248426840261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21248426840261 is an equidigital number, since it uses as much as digits as its factorization.

21248426840261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2359296, while the sum is 50.

The spelling of 21248426840261 in words is "twenty-one trillion, two hundred forty-eight billion, four hundred twenty-six million, eight hundred forty thousand, two hundred sixty-one".