2000209921 has 4 divisors (see below), whose sum is σ = 2000421844. Its totient is φ = 1999998000.

The previous prime is 2000209909. The next prime is 2000209951. The reversal of 2000209921 is 1299020002.

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 1539463696 + 460746225 = 39236^2 + 21465^2 .

It is a cyclic number.

It is not a de Polignac number, because 2000209921 - 2⁷ = 2000209793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2000209951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91110 + ... + 110911.

It is an arithmetic number, because the mean of its divisors is an integer number (500105461).

Almost surely, 2^2000209921 is an apocalyptic number.

It is an amenable number.

2000209921 is a deficient number, since it is larger than the sum of its proper divisors (211923).

2000209921 is an equidigital number, since it uses as much as digits as its factorization.

2000209921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211922.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 2000209921 is about 44723.7064765433. The cubic root of 2000209921 is about 1259.9651290005.

Adding to 2000209921 its reverse (1299020002), we get a palindrome (3299229923).

The spelling of 2000209921 in words is "two billion, two hundred nine thousand, nine hundred twenty-one".