18018020 has 24 divisors (see below), whose sum is σ = 38076864. Its totient is φ = 7161696.

The previous prime is 18018017. The next prime is 18018029. The reversal of 18018020 is 2081081.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 18017983 and 18018001.

It is not an unprimeable number, because it can be changed into a prime (18018029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 497 + ... + 6023.

It is an arithmetic number, because the mean of its divisors is an integer number (1586536).

Almost surely, 2^18018020 is an apocalyptic number.

18018020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18018020 is an abundant number, since it is smaller than the sum of its proper divisors (20058844).

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

18018020 is a wasteful number, since it uses less digits than its factorization.

18018020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5699 (or 5697 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 18018020 is about 4244.7638332421. The cubic root of 18018020 is about 262.1615653640.

The spelling of 18018020 in words is "eighteen million, eighteen thousand, twenty".