20002001 has 4 divisors (see below), whose sum is σ = 20103732. Its totient is φ = 19900272.

The previous prime is 20001983. The next prime is 20002007. The reversal of 20002001 is 10020002.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11730625 + 8271376 = 3425^2 + 2876^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002001 - 2⁶ = 20001937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20002007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50570 + ... + 50963.

It is an arithmetic number, because the mean of its divisors is an integer number (5025933).

Almost surely, 2^20002001 is an apocalyptic number.

It is an amenable number.

20002001 is a deficient number, since it is larger than the sum of its proper divisors (101731).

20002001 is a wasteful number, since it uses less digits than its factorization.

20002001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101730.

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 20002001 is about 4472.3596680052. The cubic root of 20002001 is about 271.4508139404.

Adding to 20002001 its reverse (10020002), we get a palindrome (30022003).

Multiplying 20002001 by its reverse (10020002), we get a palindrome (200420090024002).

The spelling of 20002001 in words is "twenty million, two thousand, one".