8720417 has 2 divisors, whose sum is σ = 8720418. Its totient is φ = 8720416.

The previous prime is 8720407. The next prime is 8720429. The reversal of 8720417 is 7140278.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8579041 + 141376 = 2929^2 + 376^2 .

It is a cyclic number.

It is not a de Polignac number, because 8720417 - 2⁸ = 8720161 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8720417.

It is not a weakly prime, because it can be changed into another prime (8720407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360208 + 4360209.

It is an arithmetic number, because the mean of its divisors is an integer number (4360209).

Almost surely, 2^8720417 is an apocalyptic number.

It is an amenable number.

8720417 is a deficient number, since it is larger than the sum of its proper divisors (1).

8720417 is an equidigital number, since it uses as much as digits as its factorization.

8720417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 8720417 is about 2953.0352182119. The cubic root of 8720417 is about 205.8317742437.

The spelling of 8720417 in words is "eight million, seven hundred twenty thousand, four hundred seventeen".