18955638 has 48 divisors (see below), whose sum is σ = 45012240. Its totient is φ = 5729472.

The previous prime is 18955627. The next prime is 18955661. The reversal of 18955638 is 83655981.

18955638 is a `hidden beast` number, since 1 + 8 + 9 + 5 + 5 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 18955593 and 18955602.

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 23 ways as a sum of consecutive naturals, for example, 13120 + ... + 14492.

It is an arithmetic number, because the mean of its divisors is an integer number (937755).

Almost surely, 2^18955638 is an apocalyptic number.

18955638 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 18955638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22506120).

18955638 is an abundant number, since it is smaller than the sum of its proper divisors (26056602).

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

18955638 is a wasteful number, since it uses less digits than its factorization.

18955638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1453 (or 1450 counting only the distinct ones).

The product of its digits is 259200, while the sum is 45.

The square root of 18955638 is about 4353.8072993645. The cubic root of 18955638 is about 266.6323264808.

The spelling of 18955638 in words is "eighteen million, nine hundred fifty-five thousand, six hundred thirty-eight".