2509521 has 16 divisors (see below), whose sum is σ = 3878784. Its totient is φ = 1413504.

The previous prime is 2509519. The next prime is 2509531. The reversal of 2509521 is 1259052.

It is not a de Polignac number, because 2509521 - 2¹ = 2509519 is a prime.

It is a Curzon number.

2509521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2509491 and 2509500.

It is not an unprimeable number, because it can be changed into a prime (2509531) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 715 + ... + 2351.

It is an arithmetic number, because the mean of its divisors is an integer number (242424).

2^2509521 is an apocalyptic number.

2509521 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2509521 is a deficient number, since it is larger than the sum of its proper divisors (1369263).

2509521 is a wasteful number, since it uses less digits than its factorization.

2509521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 2509521 is about 1584.1467735030. The cubic root of 2509521 is about 135.8929557051.

The spelling of 2509521 in words is "two million, five hundred nine thousand, five hundred twenty-one".