2508721 has 4 divisors (see below), whose sum is σ = 2513700. Its totient is φ = 2503744.

The previous prime is 2508697. The next prime is 2508743. The reversal of 2508721 is 1278052.

2508721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 291600 + 2217121 = 540^2 + 1489^2 .

It is a cyclic number.

It is not a de Polignac number, because 2508721 - 2⁵ = 2508689 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 (2508521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1636 + ... + 2773.

It is an arithmetic number, because the mean of its divisors is an integer number (628425).

2^2508721 is an apocalyptic number.

It is an amenable number.

2508721 is a deficient number, since it is larger than the sum of its proper divisors (4979).

2508721 is an equidigital number, since it uses as much as digits as its factorization.

2508721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4978.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 2508721 is about 1583.8942515206. The cubic root of 2508721 is about 135.8785139161.

The spelling of 2508721 in words is "two million, five hundred eight thousand, seven hundred twenty-one".