2081521 has 4 divisors (see below), whose sum is σ = 2241652. Its totient is φ = 1921392.

The previous prime is 2081491. The next prime is 2081537. The reversal of 2081521 is 1251802.

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 404496 + 1677025 = 636^2 + 1295^2 .

It is a cyclic number.

It is not a de Polignac number, because 2081521 - 2¹⁷ = 1950449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2081561) 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, 80046 + ... + 80071.

It is an arithmetic number, because the mean of its divisors is an integer number (560413).

2^2081521 is an apocalyptic number.

It is an amenable number.

2081521 is a deficient number, since it is larger than the sum of its proper divisors (160131).

2081521 is a wasteful number, since it uses less digits than its factorization.

2081521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160130.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 2081521 is about 1442.7477256957. The cubic root of 2081521 is about 127.6811931045.

The spelling of 2081521 in words is "two million, eighty-one thousand, five hundred twenty-one".