66565885 has 4 divisors (see below), whose sum is σ = 79879068. Its totient is φ = 53252704.

The previous prime is 66565867. The next prime is 66565901. The reversal of 66565885 is 58856566.

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 14884164 + 51681721 = 3858^2 + 7189^2 .

It is a cyclic number.

It is not a de Polignac number, because 66565885 - 2¹⁹ = 66041597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6656584 + ... + 6656593.

It is an arithmetic number, because the mean of its divisors is an integer number (19969767).

Almost surely, 2^66565885 is an apocalyptic number.

It is an amenable number.

66565885 is a deficient number, since it is larger than the sum of its proper divisors (13313183).

66565885 is a wasteful number, since it uses less digits than its factorization.

66565885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13313182.

The product of its digits is 1728000, while the sum is 49.

The square root of 66565885 is about 8158.7918836063. The cubic root of 66565885 is about 405.2757051727.

The spelling of 66565885 in words is "sixty-six million, five hundred sixty-five thousand, eight hundred eighty-five".