18639344 has 60 divisors (see below), whose sum is σ = 39971400. Its totient is φ = 8408064.

The previous prime is 18639331. The next prime is 18639347. The reversal of 18639344 is 44393681.

It is a junction number, because it is equal to n+sod(n) for n = 18639298 and 18639307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18639347) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134027 + ... + 134165.

It is an arithmetic number, because the mean of its divisors is an integer number (666190).

Almost surely, 2^18639344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18639344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19985700).

18639344 is an abundant number, since it is smaller than the sum of its proper divisors (21332056).

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

18639344 is a wasteful number, since it uses less digits than its factorization.

18639344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 187 counting only the distinct ones).

The product of its digits is 62208, while the sum is 38.

The square root of 18639344 is about 4317.3306567832. The cubic root of 18639344 is about 265.1409905965.

The spelling of 18639344 in words is "eighteen million, six hundred thirty-nine thousand, three hundred forty-four".