18427640 has 128 divisors (see below), whose sum is σ = 53637120. Its totient is φ = 5529600.

The previous prime is 18427631. The next prime is 18427679. The reversal of 18427640 is 4672481.

It is a junction number, because it is equal to n+sod(n) for n = 18427597 and 18427606.

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 31 ways as a sum of consecutive naturals, for example, 95384 + ... + 95576.

It is an arithmetic number, because the mean of its divisors is an integer number (419040).

Almost surely, 2^18427640 is an apocalyptic number.

18427640 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 18427640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26818560).

18427640 is an abundant number, since it is smaller than the sum of its proper divisors (35209480).

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

18427640 is a wasteful number, since it uses less digits than its factorization.

18427640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 18427640 is about 4292.7427129983. The cubic root of 18427640 is about 264.1333501400.

The spelling of 18427640 in words is "eighteen million, four hundred twenty-seven thousand, six hundred forty".