2001387643 has 16 divisors (see below), whose sum is σ = 2113166880. Its totient is φ = 1892590336.

The previous prime is 2001387601. The next prime is 2001387649. The reversal of 2001387643 is 3467831002.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2001387643 - 2¹⁷ = 2001256571 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001387599 and 2001387608.

It is not an unprimeable number, because it can be changed into a prime (2001387649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1685496 + ... + 1686682.

It is an arithmetic number, because the mean of its divisors is an integer number (132072930).

Almost surely, 2^2001387643 is an apocalyptic number.

2001387643 is a deficient number, since it is larger than the sum of its proper divisors (111779237).

2001387643 is a wasteful number, since it uses less digits than its factorization.

2001387643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2366.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 2001387643 is about 44736.8711802692. The cubic root of 2001387643 is about 1260.2123693016.

The spelling of 2001387643 in words is "two billion, one million, three hundred eighty-seven thousand, six hundred forty-three".