18867816 has 80 divisors (see below), whose sum is σ = 57673440. Its totient is φ = 5715360.

The previous prime is 18867811. The next prime is 18867839. The reversal of 18867816 is 61876881.

It is not an unprimeable number, because it can be changed into a prime (18867811) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5805 + ... + 8451.

It is an arithmetic number, because the mean of its divisors is an integer number (720918).

Almost surely, 2^18867816 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 18867816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28836720).

18867816 is an abundant number, since it is smaller than the sum of its proper divisors (38805624).

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

18867816 is a wasteful number, since it uses less digits than its factorization.

18867816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2676 (or 2663 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 18867816 is about 4343.7099350670. The cubic root of 18867816 is about 266.2199172518.

It can be divided in two parts, 18867 and 816, that added together give a 9-th power (19683 = 3⁹).

The spelling of 18867816 in words is "eighteen million, eight hundred sixty-seven thousand, eight hundred sixteen".