21718287852 has 24 divisors (see below), whose sum is σ = 50933249136. Its totient is φ = 7202680128.

The previous prime is 21718287847. The next prime is 21718287883. The reversal of 21718287852 is 25878281712.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21718287795 and 21718287804.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4591183 + ... + 4595910.

It is an arithmetic number, because the mean of its divisors is an integer number (2122218714).

Almost surely, 2^21718287852 is an apocalyptic number.

It is an amenable number.

21718287852 is an abundant number, since it is smaller than the sum of its proper divisors (29214961284).

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

21718287852 is a wasteful number, since it uses less digits than its factorization.

21718287852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9187297 (or 9187295 counting only the distinct ones).

The product of its digits is 1003520, while the sum is 51.

The spelling of 21718287852 in words is "twenty-one billion, seven hundred eighteen million, two hundred eighty-seven thousand, eight hundred fifty-two".