900000018 has 64 divisors (see below), whose sum is σ = 2109888000. Its totient is φ = 283586832.

The previous prime is 900000011. The next prime is 900000041. The reversal of 900000018 is 810000009.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (900000011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 757621 + ... + 758807.

It is an arithmetic number, because the mean of its divisors is an integer number (32967000).

Almost surely, 2^900000018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 900000018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1054944000).

900000018 is an abundant number, since it is smaller than the sum of its proper divisors (1209887982).

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

900000018 is a wasteful number, since it uses less digits than its factorization.

900000018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1956 (or 1950 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 900000018 is about 30000.0003000000. Note that the first 3 decimals coincide. The cubic root of 900000018 is about 965.4893910422.

Subtracting from 900000018 its sum of digits (18), we obtain a square (900000000 = 30000²).

Subtracting from 900000018 its reverse (810000009), we obtain a palindrome (90000009).

It can be divided in two parts, 90000001 and 8, that added together give a palindrome (90000009).

The spelling of 900000018 in words is "nine hundred million, eighteen", and thus it is an aban number.