18381275136 has 456 divisors, whose sum is σ = 64550215440. Its totient is φ = 5152702464.

The previous prime is 18381275131. The next prime is 18381275161. The reversal of 18381275136 is 63157218381.

It is a happy number.

18381275136 is a `hidden beast` number, since 1 + 8 + 3 + 8 + 127 + 513 + 6 = 666.

Its product of digits (241920) is a multiple of the sum of its prime factors (112).

It is a junction number, because it is equal to n+sod(n) for n = 18381275091 and 18381275100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18381275131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 346816486 + ... + 346816538.

It is an arithmetic number, because the mean of its divisors is an integer number (141557490).

Almost surely, 2^18381275136 is an apocalyptic number.

18381275136 is a gapful number since it is divisible by the number (16) 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 18381275136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32275107720).

18381275136 is an abundant number, since it is smaller than the sum of its proper divisors (46168940304).

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

18381275136 is an frugal number, since it uses more digits than its factorization.

18381275136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 65 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The spelling of 18381275136 in words is "eighteen billion, three hundred eighty-one million, two hundred seventy-five thousand, one hundred thirty-six".