8635661 has 4 divisors (see below), whose sum is σ = 8798652. Its totient is φ = 8472672.

The previous prime is 8635657. The next prime is 8635663. The reversal of 8635661 is 1665368.

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 3822025 + 4813636 = 1955^2 + 2194^2 .

It is a cyclic number.

It is not a de Polignac number, because 8635661 - 2² = 8635657 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 (8635663) 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, 81416 + ... + 81521.

It is an arithmetic number, because the mean of its divisors is an integer number (2199663).

Almost surely, 2^8635661 is an apocalyptic number.

It is an amenable number.

8635661 is a deficient number, since it is larger than the sum of its proper divisors (162991).

8635661 is a wasteful number, since it uses less digits than its factorization.

8635661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162990.

The product of its digits is 25920, while the sum is 35.

The square root of 8635661 is about 2938.6495197624. The cubic root of 8635661 is about 205.1627579159.

The spelling of 8635661 in words is "eight million, six hundred thirty-five thousand, six hundred sixty-one".