7717321 has 2 divisors, whose sum is σ = 7717322. Its totient is φ = 7717320.

The previous prime is 7717313. The next prime is 7717331. The reversal of 7717321 is 1237177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5812921 + 1904400 = 2411^2 + 1380^2 .

It is an emirp because it is prime and its reverse (1237177) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7717321 - 2³ = 7717313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7717321.

It is not a weakly prime, because it can be changed into another prime (7717331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3858660 + 3858661.

It is an arithmetic number, because the mean of its divisors is an integer number (3858661).

Almost surely, 2^7717321 is an apocalyptic number.

It is an amenable number.

7717321 is a deficient number, since it is larger than the sum of its proper divisors (1).

7717321 is an equidigital number, since it uses as much as digits as its factorization.

7717321 is an evil number, because the sum of its binary digits is even.

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

The square root of 7717321 is about 2778.0066594593. The cubic root of 7717321 is about 197.6160382033.

The spelling of 7717321 in words is "seven million, seven hundred seventeen thousand, three hundred twenty-one".