2005921 has 4 divisors (see below), whose sum is σ = 2009344. Its totient is φ = 2002500.

The previous prime is 2005919. The next prime is 2005931. The reversal of 2005921 is 1295002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2005921 - 2¹ = 2005919 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2005931) 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, 585 + ... + 2086.

It is an arithmetic number, because the mean of its divisors is an integer number (502336).

2^2005921 is an apocalyptic number.

It is an amenable number.

2005921 is a deficient number, since it is larger than the sum of its proper divisors (3423).

2005921 is an equidigital number, since it uses as much as digits as its factorization.

2005921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3422.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 2005921 is about 1416.3054049180. The cubic root of 2005921 is about 126.1163157037.

It can be divided in two parts, 2005 and 921, that added together give a triangular number (2926 = T₇₆).

The spelling of 2005921 in words is "two million, five thousand, nine hundred twenty-one".