7965721 has 2 divisors, whose sum is σ = 7965722. Its totient is φ = 7965720.

The previous prime is 7965719. The next prime is 7965743. The reversal of 7965721 is 1275697.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4260096 + 3705625 = 2064^2 + 1925^2 .

It is a cyclic number.

It is not a de Polignac number, because 7965721 - 2¹ = 7965719 is a prime.

It is a super-2 number, since 2×7965721² = 126905422099682, which contains 22 as substring.

Together with 7965719, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (7965761) 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 as a sum of consecutive naturals, namely, 3982860 + 3982861.

It is an arithmetic number, because the mean of its divisors is an integer number (3982861).

Almost surely, 2^7965721 is an apocalyptic number.

It is an amenable number.

7965721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7965721 is an equidigital number, since it uses as much as digits as its factorization.

7965721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26460, while the sum is 37.

The square root of 7965721 is about 2822.3608911690. The cubic root of 7965721 is about 199.7139326892.

The spelling of 7965721 in words is "seven million, nine hundred sixty-five thousand, seven hundred twenty-one".