18819864 has 112 divisors (see below), whose sum is σ = 60595920. Its totient is φ = 5365440.

The previous prime is 18819863. The next prime is 18819887. The reversal of 18819864 is 46891881.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18819863) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 40594 + ... + 41054.

It is an arithmetic number, because the mean of its divisors is an integer number (541035).

Almost surely, 2^18819864 is an apocalyptic number.

18819864 is a gapful number since it is divisible by the number (14) 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 18819864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30297960).

18819864 is an abundant number, since it is smaller than the sum of its proper divisors (41776056).

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

18819864 is an equidigital number, since it uses as much as digits as its factorization.

18819864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492 (or 473 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 18819864 is about 4338.1867179733. The cubic root of 18819864 is about 265.9941958897.

It can be divided in two parts, 18819 and 864, that added together give a 9-th power (19683 = 3⁹).

The spelling of 18819864 in words is "eighteen million, eight hundred nineteen thousand, eight hundred sixty-four".