2560721 has 2 divisors, whose sum is σ = 2560722. Its totient is φ = 2560720.

The previous prime is 2560697. The next prime is 2560739. The reversal of 2560721 is 1270652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2070721 + 490000 = 1439^2 + 700^2 .

It is a cyclic number.

It is not a de Polignac number, because 2560721 - 2¹⁸ = 2298577 is a prime.

It is not a weakly prime, because it can be changed into another prime (2560741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280360 + 1280361.

It is an arithmetic number, because the mean of its divisors is an integer number (1280361).

2^2560721 is an apocalyptic number.

It is an amenable number.

2560721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2560721 is an equidigital number, since it uses as much as digits as its factorization.

2560721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 2560721 is about 1600.2252966379. The cubic root of 2560721 is about 136.8109171605.

The spelling of 2560721 in words is "two million, five hundred sixty thousand, seven hundred twenty-one".