18081774438 has 128 divisors (see below), whose sum is σ = 46656110592. Its totient is φ = 4540669056.

The previous prime is 18081774437. The next prime is 18081774497. The reversal of 18081774438 is 83447718081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18081774433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2847495 + ... + 2853837.

It is an arithmetic number, because the mean of its divisors is an integer number (364500864).

Almost surely, 2^18081774438 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18081774438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23328055296).

18081774438 is an abundant number, since it is smaller than the sum of its proper divisors (28574336154).

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

18081774438 is a wasteful number, since it uses less digits than its factorization.

18081774438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6618.

The product of its (nonzero) digits is 1204224, while the sum is 51.

It can be divided in two parts, 180817 and 74438, that added together give a triangular number (255255 = T₇₁₄).

The spelling of 18081774438 in words is "eighteen billion, eighty-one million, seven hundred seventy-four thousand, four hundred thirty-eight".