7425721 has 2 divisors, whose sum is σ = 7425722. Its totient is φ = 7425720.

The previous prime is 7425707. The next prime is 7425731. The reversal of 7425721 is 1275247.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6817321 + 608400 = 2611^2 + 780^2 .

It is a cyclic number.

It is not a de Polignac number, because 7425721 - 2⁵ = 7425689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7425721.

It is not a weakly prime, because it can be changed into another prime (7425731) 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 as a sum of consecutive naturals, namely, 3712860 + 3712861.

It is an arithmetic number, because the mean of its divisors is an integer number (3712861).

Almost surely, 2^7425721 is an apocalyptic number.

It is an amenable number.

7425721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7425721 is an equidigital number, since it uses as much as digits as its factorization.

7425721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3920, while the sum is 28.

The square root of 7425721 is about 2725.0176146220. The cubic root of 7425721 is about 195.0950314794.

The spelling of 7425721 in words is "seven million, four hundred twenty-five thousand, seven hundred twenty-one".