18686616 has 64 divisors (see below), whose sum is σ = 50893920. Its totient is φ = 5683200.

The previous prime is 18686609. The next prime is 18686627. The reversal of 18686616 is 61668681.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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, 31216 + ... + 31808.

Almost surely, 2^18686616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18686616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25446960).

18686616 is an abundant number, since it is smaller than the sum of its proper divisors (32207304).

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

18686616 is a wasteful number, since it uses less digits than its factorization.

18686616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716 (or 712 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 18686616 is about 4322.8018691585. The cubic root of 18686616 is about 265.3649463328.

The spelling of 18686616 in words is "eighteen million, six hundred eighty-six thousand, six hundred sixteen".