18389820 has 48 divisors (see below), whose sum is σ = 53157888. Its totient is φ = 4745280.

The previous prime is 18389809. The next prime is 18389821. The reversal of 18389820 is 2898381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18389821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3084 + ... + 6803.

It is an arithmetic number, because the mean of its divisors is an integer number (1107456).

Almost surely, 2^18389820 is an apocalyptic number.

18389820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18389820 is an abundant number, since it is smaller than the sum of its proper divisors (34768068).

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

18389820 is a wasteful number, since it uses less digits than its factorization.

18389820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9930 (or 9928 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 18389820 is about 4288.3353413650. The cubic root of 18389820 is about 263.9525281952.

The spelling of 18389820 in words is "eighteen million, three hundred eighty-nine thousand, eight hundred twenty".