21042500263 has 16 divisors (see below), whose sum is σ = 21330666720. Its totient is φ = 20756736000.

The previous prime is 21042500221. The next prime is 21042500293. The reversal of 21042500263 is 36200524012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21042500263 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 (21042500203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20854303 + ... + 20855311.

It is an arithmetic number, because the mean of its divisors is an integer number (1333166670).

Almost surely, 2^21042500263 is an apocalyptic number.

21042500263 is a deficient number, since it is larger than the sum of its proper divisors (288166457).

21042500263 is a wasteful number, since it uses less digits than its factorization.

21042500263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1938.

The product of its (nonzero) digits is 2880, while the sum is 25.

The spelling of 21042500263 in words is "twenty-one billion, forty-two million, five hundred thousand, two hundred sixty-three".