2015521 has 4 divisors (see below), whose sum is σ = 2020032. Its totient is φ = 2011012.

The previous prime is 2015509. The next prime is 2015543. The reversal of 2015521 is 1255102.

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 2015521 - 2⁷ = 2015393 is a prime.

It is a Duffinian number.

2015521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2015495 and 2015504.

It is not an unprimeable number, because it can be changed into a prime (2015021) 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, 1501 + ... + 2506.

It is an arithmetic number, because the mean of its divisors is an integer number (505008).

2^2015521 is an apocalyptic number.

It is an amenable number.

2015521 is a deficient number, since it is larger than the sum of its proper divisors (4511).

2015521 is an equidigital number, since it uses as much as digits as its factorization.

2015521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4510.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 2015521 is about 1419.6904592199. The cubic root of 2015521 is about 126.3171860804.

The spelling of 2015521 in words is "two million, fifteen thousand, five hundred twenty-one".