65561566 has 16 divisors (see below), whose sum is σ = 112581504. Its totient is φ = 28050264.

The previous prime is 65561563. The next prime is 65561579. The reversal of 65561566 is 66516556.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65561563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5361 + ... + 12643.

It is an arithmetic number, because the mean of its divisors is an integer number (7036344).

Almost surely, 2^65561566 is an apocalyptic number.

65561566 is a deficient number, since it is larger than the sum of its proper divisors (47019938).

65561566 is a wasteful number, since it uses less digits than its factorization.

65561566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7935.

The product of its digits is 162000, while the sum is 40.

The square root of 65561566 is about 8097.0096949429. The cubic root of 65561566 is about 403.2271561387.

The spelling of 65561566 in words is "sixty-five million, five hundred sixty-one thousand, five hundred sixty-six".