2001535540 has 48 divisors (see below), whose sum is σ = 4322110464. Its totient is φ = 778118400.

The previous prime is 2001535451. The next prime is 2001535559. The reversal of 2001535540 is 455351002.

It is a super-2 number, since 2×2001535540² = 8012289035766183200, which contains 22 as substring.

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, 217717 + ... + 226723.

It is an arithmetic number, because the mean of its divisors is an integer number (90043968).

Almost surely, 2^2001535540 is an apocalyptic number.

2001535540 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 2001535540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2161055232).

2001535540 is an abundant number, since it is smaller than the sum of its proper divisors (2320574924).

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

2001535540 is a wasteful number, since it uses less digits than its factorization.

2001535540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9328 (or 9326 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 2001535540 is about 44738.5241151292. The cubic root of 2001535540 is about 1260.2434106041.

Adding to 2001535540 its reverse (455351002), we get a palindrome (2456886542).

It can be divided in two parts, 20015 and 35540, that added together give a palindrome (55555).

The spelling of 2001535540 in words is "two billion, one million, five hundred thirty-five thousand, five hundred forty".