2001515540 has 12 divisors (see below), whose sum is σ = 4203182676. Its totient is φ = 800606208.

The previous prime is 2001515513. The next prime is 2001515543. The reversal of 2001515540 is 455151002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 727596676 + 1273918864 = 26974^2 + 35692^2 .

It is a super-2 number, since 2×2001515540² = 8012128913722983200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001515543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50037869 + ... + 50037908.

It is an arithmetic number, because the mean of its divisors is an integer number (350265223).

Almost surely, 2^2001515540 is an apocalyptic number.

2001515540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001515540 is an abundant number, since it is smaller than the sum of its proper divisors (2201667136).

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

2001515540 is a wasteful number, since it uses less digits than its factorization.

2001515540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100075786 (or 100075784 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 2001515540 is about 44738.3005935630. The cubic root of 2001515540 is about 1260.2392130016.

Adding to 2001515540 its reverse (455151002), we get a palindrome (2456666542).

The spelling of 2001515540 in words is "two billion, one million, five hundred fifteen thousand, five hundred forty".