2001687 has 4 divisors (see below), whose sum is σ = 2668920. Its totient is φ = 1334456.

The previous prime is 2001677. The next prime is 2001691. The reversal of 2001687 is 7861002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2001687 - 2¹² = 1997591 is a prime.

It is an Ulam number.

It is a D-number.

2001687 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001617) 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, 333612 + ... + 333617.

It is an arithmetic number, because the mean of its divisors is an integer number (667230).

2^2001687 is an apocalyptic number.

2001687 is a deficient number, since it is larger than the sum of its proper divisors (667233).

2001687 is an equidigital number, since it uses as much as digits as its factorization.

2001687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667232.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 2001687 is about 1414.8098812208. The cubic root of 2001687 is about 126.0275198141.

Adding to 2001687 its reverse (7861002), we get a palindrome (9862689).

The spelling of 2001687 in words is "two million, one thousand, six hundred eighty-seven".