21716887518 has 24 divisors (see below), whose sum is σ = 47072425608. Its totient is φ = 7236013392.

The previous prime is 21716887513. The next prime is 21716887519. The reversal of 21716887518 is 81578861712.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716887513) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 200121 + ... + 288932.

It is an arithmetic number, because the mean of its divisors is an integer number (1961351067).

Almost surely, 2^21716887518 is an apocalyptic number.

21716887518 is an abundant number, since it is smaller than the sum of its proper divisors (25355538090).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21716887518 is a wasteful number, since it uses less digits than its factorization.

21716887518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491528 (or 491525 counting only the distinct ones).

The product of its digits is 1505280, while the sum is 54.

The spelling of 21716887518 in words is "twenty-one billion, seven hundred sixteen million, eight hundred eighty-seven thousand, five hundred eighteen".