18685540 has 12 divisors (see below), whose sum is σ = 39239676. Its totient is φ = 7474208.

The previous prime is 18685519. The next prime is 18685549. The reversal of 18685540 is 4558681.

It can be written as a sum of positive squares in 2 ways, for example, as 2509056 + 16176484 = 1584^2 + 4022^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18685540.

It is not an unprimeable number, because it can be changed into a prime (18685549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467119 + ... + 467158.

It is an arithmetic number, because the mean of its divisors is an integer number (3269973).

Almost surely, 2^18685540 is an apocalyptic number.

18685540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18685540 is an abundant number, since it is smaller than the sum of its proper divisors (20554136).

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

18685540 is a wasteful number, since it uses less digits than its factorization.

18685540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 934286 (or 934284 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 37.

The square root of 18685540 is about 4322.6774110498. The cubic root of 18685540 is about 265.3598528805.

The spelling of 18685540 in words is "eighteen million, six hundred eighty-five thousand, five hundred forty".