18331000 has 64 divisors (see below), whose sum is σ = 44815680. Its totient is φ = 7004800.

The previous prime is 18330979. The next prime is 18331003. The reversal of 18331000 is 13381.

It is a super-2 number, since 2×18331000² = 672051122000000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18331003) 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, 22602 + ... + 23398.

It is an arithmetic number, because the mean of its divisors is an integer number (700245).

Almost surely, 2^18331000 is an apocalyptic number.

18331000 is a gapful number since it is divisible by the number (10) 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 18331000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22407840).

18331000 is an abundant number, since it is smaller than the sum of its proper divisors (26484680).

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

18331000 is a wasteful number, since it uses less digits than its factorization.

18331000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841 (or 827 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 18331000 is about 4281.4717095877. The cubic root of 18331000 is about 263.6708094653.

Adding to 18331000 its reverse (13381), we get a palindrome (18344381).

The spelling of 18331000 in words is "eighteen million, three hundred thirty-one thousand".