18145638 has 24 divisors (see below), whose sum is σ = 44932368. Its totient is φ = 5184432.

The previous prime is 18145637. The next prime is 18145661. The reversal of 18145638 is 83654181.

18145638 is a `hidden beast` number, since 1 + 8 + 14 + 5 + 638 = 666.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18145637) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 71881 + ... + 72132.

It is an arithmetic number, because the mean of its divisors is an integer number (1872182).

Almost surely, 2^18145638 is an apocalyptic number.

18145638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18145638 is an abundant number, since it is smaller than the sum of its proper divisors (26786730).

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

18145638 is a wasteful number, since it uses less digits than its factorization.

18145638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144028 (or 144025 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 18145638 is about 4259.7697120854. The cubic root of 18145638 is about 262.7790556204.

The spelling of 18145638 in words is "eighteen million, one hundred forty-five thousand, six hundred thirty-eight".