18438338880 has 448 divisors, whose sum is σ = 70613625600. Its totient is φ = 4502200320.

The previous prime is 18438338879. The next prime is 18438338887. The reversal of 18438338880 is 8883383481.

18438338880 is a `hidden beast` number, since 184 + 3 + 8 + 3 + 388 + 80 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18438338887) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15611890 + ... + 15613070.

It is an arithmetic number, because the mean of its divisors is an integer number (157619700).

Almost surely, 2^18438338880 is an apocalyptic number.

18438338880 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 18438338880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35306812800).

18438338880 is an abundant number, since it is smaller than the sum of its proper divisors (52175286720).

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

18438338880 is a wasteful number, since it uses less digits than its factorization.

18438338880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1359 (or 1343 counting only the distinct ones).

The product of its (nonzero) digits is 3538944, while the sum is 54.

The spelling of 18438338880 in words is "eighteen billion, four hundred thirty-eight million, three hundred thirty-eight thousand, eight hundred eighty".