18438551040 has 480 divisors, whose sum is σ = 73863709920. Its totient is φ = 3889299456.

The previous prime is 18438551009. The next prime is 18438551041. The reversal of 18438551040 is 4015583481.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is a self number, because there is not a number n which added to its sum of digits gives 18438551040.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18438551041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4890276 + ... + 4894044.

It is an arithmetic number, because the mean of its divisors is an integer number (153882729).

Almost surely, 2^18438551040 is an apocalyptic number.

18438551040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18438551040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36931854960).

18438551040 is an abundant number, since it is smaller than the sum of its proper divisors (55425158880).

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

18438551040 is a wasteful number, since it uses less digits than its factorization.

18438551040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3822 (or 3799 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 39.

The spelling of 18438551040 in words is "eighteen billion, four hundred thirty-eight million, five hundred fifty-one thousand, forty".