18117540 has 96 divisors (see below), whose sum is σ = 64431360. Its totient is φ = 4140288.

The previous prime is 18117523. The next prime is 18117559. The reversal of 18117540 is 4571181.

18117540 is a `hidden beast` number, since 1 + 8 + 117 + 540 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1384 + ... + 6176.

It is an arithmetic number, because the mean of its divisors is an integer number (671160).

Almost surely, 2^18117540 is an apocalyptic number.

18117540 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 18117540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32215680).

18117540 is an abundant number, since it is smaller than the sum of its proper divisors (46313820).

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

18117540 is a wasteful number, since it uses less digits than its factorization.

18117540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4818 (or 4810 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 18117540 is about 4256.4703687445. The cubic root of 18117540 is about 262.6433502741.

The spelling of 18117540 in words is "eighteen million, one hundred seventeen thousand, five hundred forty".