18840636 has 18 divisors (see below), whose sum is σ = 47625032. Its totient is φ = 6280200.

The previous prime is 18840629. The next prime is 18840637. The reversal of 18840636 is 63604881.

It is a happy number.

18840636 is a `hidden beast` number, since 18 + 8 + 4 + 0 + 636 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 523351 = 18840636 / (1 + 8 + 8 + 4 + 0 + 6 + 3 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 18840636.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18840637) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 261640 + ... + 261711.

Almost surely, 2^18840636 is an apocalyptic number.

It is an amenable number.

18840636 is an abundant number, since it is smaller than the sum of its proper divisors (28784396).

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

18840636 is a wasteful number, since it uses less digits than its factorization.

18840636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523361 (or 523356 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 18840636 is about 4340.5801455566. The cubic root of 18840636 is about 266.0920216037.

The spelling of 18840636 in words is "eighteen million, eight hundred forty thousand, six hundred thirty-six".