8720669 has 4 divisors (see below), whose sum is σ = 8727420. Its totient is φ = 8713920.

The previous prime is 8720629. The next prime is 8720671. The reversal of 8720669 is 9660278.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1295044 + 7425625 = 1138^2 + 2725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8720669 is a prime.

It is a super-2 number, since 2×8720669² = 152100135615122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8720629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 764 + ... + 4245.

It is an arithmetic number, because the mean of its divisors is an integer number (2181855).

Almost surely, 2^8720669 is an apocalyptic number.

It is an amenable number.

8720669 is a deficient number, since it is larger than the sum of its proper divisors (6751).

8720669 is a wasteful number, since it uses less digits than its factorization.

8720669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6750.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 8720669 is about 2953.0778858676. The cubic root of 8720669 is about 205.8337569130.

The spelling of 8720669 in words is "eight million, seven hundred twenty thousand, six hundred sixty-nine".