21615549326263 has 2 divisors, whose sum is σ = 21615549326264. Its totient is φ = 21615549326262.

The previous prime is 21615549326257. The next prime is 21615549326369. The reversal of 21615549326263 is 36262394551612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21615549326263 is a prime.

It is a super-2 number, since 2×21615549326263² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21615549326213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10807774663131 + 10807774663132.

It is an arithmetic number, because the mean of its divisors is an integer number (10807774663132).

Almost surely, 2^{21615549326263} is an apocalyptic number.

21615549326263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21615549326263 is an equidigital number, since it uses as much as digits as its factorization.

21615549326263 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13996800, while the sum is 55.

The spelling of 21615549326263 in words is "twenty-one trillion, six hundred fifteen billion, five hundred forty-nine million, three hundred twenty-six thousand, two hundred sixty-three".