18523840 has 56 divisors (see below), whose sum is σ = 44604432. Its totient is φ = 7326720.

The previous prime is 18523777. The next prime is 18523847. The reversal of 18523840 is 4832581.

It is not an unprimeable number, because it can be changed into a prime (18523847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33970 + ... + 34510.

Almost surely, 2^18523840 is an apocalyptic number.

18523840 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 18523840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22302216).

18523840 is an abundant number, since it is smaller than the sum of its proper divisors (26080592).

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

18523840 is a wasteful number, since it uses less digits than its factorization.

18523840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 18523840 is about 4303.9330849817. The cubic root of 18523840 is about 264.5921815436.

It can be divided in two parts, 185 and 23840, that added together give a square (24025 = 155²).

The spelling of 18523840 in words is "eighteen million, five hundred twenty-three thousand, eight hundred forty".