8661566 has 4 divisors (see below), whose sum is σ = 12992352. Its totient is φ = 4330782.

The previous prime is 8661557. The next prime is 8661571. The reversal of 8661566 is 6651668.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2165390 + ... + 2165393.

It is an arithmetic number, because the mean of its divisors is an integer number (3248088).

Almost surely, 2^8661566 is an apocalyptic number.

8661566 is a deficient number, since it is larger than the sum of its proper divisors (4330786).

8661566 is a wasteful number, since it uses less digits than its factorization.

8661566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4330785.

The product of its digits is 51840, while the sum is 38.

The square root of 8661566 is about 2943.0538561161. The cubic root of 8661566 is about 205.3677001799.

The spelling of 8661566 in words is "eight million, six hundred sixty-one thousand, five hundred sixty-six".