21515748263 has 2 divisors, whose sum is σ = 21515748264. Its totient is φ = 21515748262.

The previous prime is 21515748253. The next prime is 21515748283. The reversal of 21515748263 is 36284751512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21515748263 - 2¹² = 21515744167 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21515748203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10757874131 + 10757874132.

It is an arithmetic number, because the mean of its divisors is an integer number (10757874132).

Almost surely, 2^21515748263 is an apocalyptic number.

21515748263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515748263 is an equidigital number, since it uses as much as digits as its factorization.

21515748263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 44.

The spelling of 21515748263 in words is "twenty-one billion, five hundred fifteen million, seven hundred forty-eight thousand, two hundred sixty-three".