8520661 has 4 divisors (see below), whose sum is σ = 8728524. Its totient is φ = 8312800.

The previous prime is 8520653. The next prime is 8520679. The reversal of 8520661 is 1660258.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 398161 + 8122500 = 631^2 + 2850^2 .

It is a cyclic number.

It is not a de Polignac number, because 8520661 - 2³ = 8520653 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8520761) 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, 103870 + ... + 103951.

It is an arithmetic number, because the mean of its divisors is an integer number (2182131).

Almost surely, 2^8520661 is an apocalyptic number.

It is an amenable number.

8520661 is a deficient number, since it is larger than the sum of its proper divisors (207863).

8520661 is a wasteful number, since it uses less digits than its factorization.

8520661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207862.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 8520661 is about 2919.0171291036. The cubic root of 8520661 is about 204.2479763511.

The spelling of 8520661 in words is "eight million, five hundred twenty thousand, six hundred sixty-one".