8720513 has 2 divisors, whose sum is σ = 8720514. Its totient is φ = 8720512.

The previous prime is 8720497. The next prime is 8720531. The reversal of 8720513 is 3150278.

Together with next prime (8720531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6385729 + 2334784 = 2527^2 + 1528^2 .

It is a cyclic number.

It is not a de Polignac number, because 8720513 - 2⁴ = 8720497 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (8720533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360256 + 4360257.

It is an arithmetic number, because the mean of its divisors is an integer number (4360257).

Almost surely, 2^8720513 is an apocalyptic number.

It is an amenable number.

8720513 is a deficient number, since it is larger than the sum of its proper divisors (1).

8720513 is an equidigital number, since it uses as much as digits as its factorization.

8720513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 8720513 is about 2953.0514726296. The cubic root of 8720513 is about 205.8325295508.

The spelling of 8720513 in words is "eight million, seven hundred twenty thousand, five hundred thirteen".