18215640534 has 48 divisors (see below), whose sum is σ = 45639196848. Its totient is φ = 4804123968.

The previous prime is 18215640511. The next prime is 18215640563. The reversal of 18215640534 is 43504651281.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 18215640492 and 18215640501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2379177 + ... + 2386820.

It is an arithmetic number, because the mean of its divisors is an integer number (950816601).

Almost surely, 2^18215640534 is an apocalyptic number.

18215640534 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

18215640534 is an abundant number, since it is smaller than the sum of its proper divisors (27423556314).

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

18215640534 is a wasteful number, since it uses less digits than its factorization.

18215640534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4766029 (or 4766022 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 39.

The spelling of 18215640534 in words is "eighteen billion, two hundred fifteen million, six hundred forty thousand, five hundred thirty-four".