18136440 has 128 divisors (see below), whose sum is σ = 69120000. Its totient is φ = 4143744.

The previous prime is 18136439. The next prime is 18136463. The reversal of 18136440 is 4463181.

18136440 is a `hidden beast` number, since 1 + 8 + 13 + 644 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 6361 + ... + 8759.

It is an arithmetic number, because the mean of its divisors is an integer number (540000).

Almost surely, 2^18136440 is an apocalyptic number.

18136440 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 18136440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34560000).

18136440 is an abundant number, since it is smaller than the sum of its proper divisors (50983560).

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

18136440 is a wasteful number, since it uses less digits than its factorization.

18136440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2426 (or 2416 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 18136440 is about 4258.6899394062. The cubic root of 18136440 is about 262.7346473304.

The spelling of 18136440 in words is "eighteen million, one hundred thirty-six thousand, four hundred forty".