21818129886 has 24 divisors (see below), whose sum is σ = 54025845744. Its totient is φ = 6233751360.

The previous prime is 21818129881. The next prime is 21818129909. The reversal of 21818129886 is 68892181812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21818129881) 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, 86579755 + ... + 86580006.

It is an arithmetic number, because the mean of its divisors is an integer number (2251076906).

Almost surely, 2^21818129886 is an apocalyptic number.

21818129886 is an abundant number, since it is smaller than the sum of its proper divisors (32207715858).

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

21818129886 is a wasteful number, since it uses less digits than its factorization.

21818129886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173159776 (or 173159773 counting only the distinct ones).

The product of its digits is 884736, while the sum is 54.

The spelling of 21818129886 in words is "twenty-one billion, eight hundred eighteen million, one hundred twenty-nine thousand, eight hundred eighty-six".