21361266263 has 2 divisors, whose sum is σ = 21361266264. Its totient is φ = 21361266262.

The previous prime is 21361266259. The next prime is 21361266271. The reversal of 21361266263 is 36266216312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21361266263 - 2² = 21361266259 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21361266233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680633131 + 10680633132.

It is an arithmetic number, because the mean of its divisors is an integer number (10680633132).

Almost surely, 2^21361266263 is an apocalyptic number.

21361266263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21361266263 is an equidigital number, since it uses as much as digits as its factorization.

21361266263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 38.

The spelling of 21361266263 in words is "twenty-one billion, three hundred sixty-one million, two hundred sixty-six thousand, two hundred sixty-three".