18215781852 has 12 divisors (see below), whose sum is σ = 42503491016. Its totient is φ = 6071927280.

The previous prime is 18215781851. The next prime is 18215781887. The reversal of 18215781852 is 25818751281.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18215781851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 758990899 + ... + 758990922.

Almost surely, 2^18215781852 is an apocalyptic number.

18215781852 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18215781852 is an abundant number, since it is smaller than the sum of its proper divisors (24287709164).

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

18215781852 is a wasteful number, since it uses less digits than its factorization.

18215781852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517981828 (or 1517981826 counting only the distinct ones).

The product of its digits is 358400, while the sum is 48.

The spelling of 18215781852 in words is "eighteen billion, two hundred fifteen million, seven hundred eighty-one thousand, eight hundred fifty-two".