18823840 has 84 divisors (see below), whose sum is σ = 51883146. Its totient is φ = 6453888.

The previous prime is 18823799. The next prime is 18823841. The reversal of 18823840 is 4832881.

It can be written as a sum of positive squares in only one way, i.e., 16941456 + 1882384 = 4116^2 + 1372^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18823796 and 18823805.

It is not an unprimeable number, because it can be changed into a prime (18823841) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 2689117 + ... + 2689123.

Almost surely, 2^18823840 is an apocalyptic number.

18823840 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 18823840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25941573).

18823840 is an abundant number, since it is smaller than the sum of its proper divisors (33059306).

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

18823840 is an frugal number, since it uses more digits than its factorization.

18823840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 14 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 18823840 is about 4338.6449497510. The cubic root of 18823840 is about 266.0129264263.

The spelling of 18823840 in words is "eighteen million, eight hundred twenty-three thousand, eight hundred forty".