7713721 has 2 divisors, whose sum is σ = 7713722. Its totient is φ = 7713720.

The previous prime is 7713709. The next prime is 7713743. The reversal of 7713721 is 1273177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7502121 + 211600 = 2739^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 7713721 - 2⁵ = 7713689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7713721.

It is not a weakly prime, because it can be changed into another prime (7713701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3856860 + 3856861.

It is an arithmetic number, because the mean of its divisors is an integer number (3856861).

Almost surely, 2^7713721 is an apocalyptic number.

It is an amenable number.

7713721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7713721 is an equidigital number, since it uses as much as digits as its factorization.

7713721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2058, while the sum is 28.

The square root of 7713721 is about 2777.3586372667. The cubic root of 7713721 is about 197.5853052418.

Adding to 7713721 its reverse (1273177), we get a palindrome (8986898).

The spelling of 7713721 in words is "seven million, seven hundred thirteen thousand, seven hundred twenty-one".