20331040 has 48 divisors (see below), whose sum is σ = 49593600. Its totient is φ = 7868160.

The previous prime is 20331023. The next prime is 20331043. The reversal of 20331040 is 4013302.

It is a self number, because there is not a number n which added to its sum of digits gives 20331040.

It is not an unprimeable number, because it can be changed into a prime (20331043) 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, 2911 + ... + 7009.

It is an arithmetic number, because the mean of its divisors is an integer number (1033200).

Almost surely, 2^20331040 is an apocalyptic number.

20331040 is a gapful number since it is divisible by the number (20) 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 20331040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24796800).

20331040 is an abundant number, since it is smaller than the sum of its proper divisors (29262560).

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

20331040 is a wasteful number, since it uses less digits than its factorization.

20331040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4145 (or 4137 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 20331040 is about 4508.9954535351. The cubic root of 20331040 is about 272.9312085434.

Adding to 20331040 its reverse (4013302), we get a palindrome (24344342).

The spelling of 20331040 in words is "twenty million, three hundred thirty-one thousand, forty".