18002000 has 40 divisors (see below), whose sum is σ = 43533672. Its totient is φ = 7200000.

The previous prime is 18001999. The next prime is 18002003. The reversal of 18002000 is 20081.

It can be written as a sum of positive squares in 4 ways, for example, as 2572816 + 15429184 = 1604^2 + 3928^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18002003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2501 + ... + 6500.

Almost surely, 2^18002000 is an apocalyptic number.

18002000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18002000 is an abundant number, since it is smaller than the sum of its proper divisors (25531672).

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

18002000 is an equidigital number, since it uses as much as digits as its factorization.

18002000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9024 (or 9008 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 18002000 is about 4242.8763828328. The cubic root of 18002000 is about 262.0838455110.

Adding to 18002000 its reverse (20081), we get a palindrome (18022081).

The spelling of 18002000 in words is "eighteen million, two thousand".