18405238836 has 96 divisors (see below), whose sum is σ = 46204929792. Its totient is φ = 5681428480.

The previous prime is 18405238829. The next prime is 18405238843. The reversal of 18405238836 is 63883250481.

It is an interprime number because it is at equal distance from previous prime (18405238829) and next prime (18405238843).

It is a super-2 number, since 2×18405238836² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9804730 + ... + 9806606.

It is an arithmetic number, because the mean of its divisors is an integer number (481301352).

Almost surely, 2^18405238836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18405238836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23102464896).

18405238836 is an abundant number, since it is smaller than the sum of its proper divisors (27799690956).

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

18405238836 is a wasteful number, since it uses less digits than its factorization.

18405238836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2649 (or 2647 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 48.

The spelling of 18405238836 in words is "eighteen billion, four hundred five million, two hundred thirty-eight thousand, eight hundred thirty-six".