20516421263 has 4 divisors (see below), whose sum is σ = 22094607528. Its totient is φ = 18938235000.

The previous prime is 20516421257. The next prime is 20516421307. The reversal of 20516421263 is 36212461502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20516421263 - 2²⁴ = 20499644047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20516421203) 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 in 3 ways as a sum of consecutive naturals, for example, 789093113 + ... + 789093138.

It is an arithmetic number, because the mean of its divisors is an integer number (5523651882).

Almost surely, 2^20516421263 is an apocalyptic number.

20516421263 is a deficient number, since it is larger than the sum of its proper divisors (1578186265).

20516421263 is a wasteful number, since it uses less digits than its factorization.

20516421263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578186264.

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 20516421263 its reverse (36212461502), we get a palindrome (56728882765).

The spelling of 20516421263 in words is "twenty billion, five hundred sixteen million, four hundred twenty-one thousand, two hundred sixty-three".