2001005720 has 64 divisors (see below), whose sum is σ = 5195473920. Its totient is φ = 679388544.

The previous prime is 2001005717. The next prime is 2001005801. The reversal of 2001005720 is 275001002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5852 + ... + 63531.

It is an arithmetic number, because the mean of its divisors is an integer number (81179280).

Almost surely, 2^2001005720 is an apocalyptic number.

2001005720 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 2001005720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2597736960).

2001005720 is an abundant number, since it is smaller than the sum of its proper divisors (3194468200).

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

2001005720 is a wasteful number, since it uses less digits than its factorization.

2001005720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69504 (or 69500 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 2001005720 is about 44732.6024282067. The cubic root of 2001005720 is about 1260.1322024718.

Adding to 2001005720 its reverse (275001002), we get a palindrome (2276006722).

The spelling of 2001005720 in words is "two billion, one million, five thousand, seven hundred twenty".