7981717 has 2 divisors, whose sum is σ = 7981718. Its totient is φ = 7981716.

The previous prime is 7981711. The next prime is 7981783. The reversal of 7981717 is 7171897.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6320196 + 1661521 = 2514^2 + 1289^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7981717 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7981717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7981711) 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, 3990858 + 3990859.

It is an arithmetic number, because the mean of its divisors is an integer number (3990859).

Almost surely, 2^7981717 is an apocalyptic number.

It is an amenable number.

7981717 is a deficient number, since it is larger than the sum of its proper divisors (1).

7981717 is an equidigital number, since it uses as much as digits as its factorization.

7981717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24696, while the sum is 40.

The square root of 7981717 is about 2825.1932677252. The cubic root of 7981717 is about 199.8475254538.

It can be divided in two parts, 79 and 81717, that added together give a square (81796 = 286²).

The spelling of 7981717 in words is "seven million, nine hundred eighty-one thousand, seven hundred seventeen".