18613638 has 40 divisors (see below), whose sum is σ = 42209640. Its totient is φ = 6130080.

The previous prime is 18613633. The next prime is 18613649. The reversal of 18613638 is 83631681.

18613638 is a `hidden beast` number, since 1 + 8 + 6 + 13 + 638 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18613633) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13773 + ... + 15063.

It is an arithmetic number, because the mean of its divisors is an integer number (1055241).

Almost surely, 2^18613638 is an apocalyptic number.

18613638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18613638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21104820).

18613638 is an abundant number, since it is smaller than the sum of its proper divisors (23596002).

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

18613638 is a wasteful number, since it uses less digits than its factorization.

18613638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1394 (or 1385 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 18613638 is about 4314.3525586118. The cubic root of 18613638 is about 265.0190469281.

It can be divided in two parts, 186 and 13638, that added together give a cube (13824 = 24³).

The spelling of 18613638 in words is "eighteen million, six hundred thirteen thousand, six hundred thirty-eight".