8720709 has 16 divisors (see below), whose sum is σ = 11993088. Its totient is φ = 5633712.

The previous prime is 8720707. The next prime is 8720713. The reversal of 8720709 is 9070278.

It is not a de Polignac number, because 8720709 - 2¹ = 8720707 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8720709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8720707) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17664 + ... + 18150.

It is an arithmetic number, because the mean of its divisors is an integer number (749568).

Almost surely, 2^8720709 is an apocalyptic number.

It is an amenable number.

8720709 is a deficient number, since it is larger than the sum of its proper divisors (3272379).

8720709 is a wasteful number, since it uses less digits than its factorization.

8720709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664.

The product of its (nonzero) digits is 7056, while the sum is 33.

The square root of 8720709 is about 2953.0846584546. The cubic root of 8720709 is about 205.8340716188.

The spelling of 8720709 in words is "eight million, seven hundred twenty thousand, seven hundred nine".