18213540 has 48 divisors (see below), whose sum is σ = 51492672. Its totient is φ = 4809856.

The previous prime is 18213499. The next prime is 18213551. The reversal of 18213540 is 4531281.

It is a self number, because there is not a number n which added to its sum of digits gives 18213540.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5002 + ... + 7838.

It is an arithmetic number, because the mean of its divisors is an integer number (1072764).

Almost surely, 2^18213540 is an apocalyptic number.

18213540 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 18213540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25746336).

18213540 is an abundant number, since it is smaller than the sum of its proper divisors (33279132).

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

18213540 is a wasteful number, since it uses less digits than its factorization.

18213540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2956 (or 2954 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 18213540 is about 4267.7324189785. The cubic root of 18213540 is about 263.1064256254.

The spelling of 18213540 in words is "eighteen million, two hundred thirteen thousand, five hundred forty".