18100638 has 32 divisors (see below), whose sum is σ = 40742400. Its totient is φ = 5955768.

The previous prime is 18100633. The next prime is 18100651. The reversal of 18100638 is 83600181.

18100638 is a `hidden beast` number, since 18 + 10 + 0 + 638 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18100633) 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 15 ways as a sum of consecutive naturals, for example, 2145 + ... + 6387.

It is an arithmetic number, because the mean of its divisors is an integer number (1273200).

Almost surely, 2^18100638 is an apocalyptic number.

18100638 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 18100638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20371200).

18100638 is an abundant number, since it is smaller than the sum of its proper divisors (22641762).

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

18100638 is a wasteful number, since it uses less digits than its factorization.

18100638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4333 (or 4327 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 18100638 is about 4254.4844576047. The cubic root of 18100638 is about 262.5616508257.

The spelling of 18100638 in words is "eighteen million, one hundred thousand, six hundred thirty-eight".