2009521 has 4 divisors (see below), whose sum is σ = 2025472. Its totient is φ = 1993572.

The previous prime is 2009509. The next prime is 2009537. The reversal of 2009521 is 1259002.

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 2009521 - 2⁵ = 2009489 is a prime.

It is a Duffinian number.

2009521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2009321) 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, 7785 + ... + 8038.

It is an arithmetic number, because the mean of its divisors is an integer number (506368).

2^2009521 is an apocalyptic number.

It is an amenable number.

2009521 is a deficient number, since it is larger than the sum of its proper divisors (15951).

2009521 is a wasteful number, since it uses less digits than its factorization.

2009521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15950.

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

The square root of 2009521 is about 1417.5757475352. The cubic root of 2009521 is about 126.1917170447.

The spelling of 2009521 in words is "two million, nine thousand, five hundred twenty-one".