66001565 has 16 divisors (see below), whose sum is σ = 95841792. Its totient is φ = 42595584.

The previous prime is 66001549. The next prime is 66001597. The reversal of 66001565 is 56510066.

It is a cyclic number.

It is not a de Polignac number, because 66001565 - 2⁴ = 66001549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54869 + ... + 56058.

It is an arithmetic number, because the mean of its divisors is an integer number (5990112).

Almost surely, 2^66001565 is an apocalyptic number.

It is an amenable number.

66001565 is a deficient number, since it is larger than the sum of its proper divisors (29840227).

66001565 is a wasteful number, since it uses less digits than its factorization.

66001565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110956.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 66001565 is about 8124.1347231567. The cubic root of 66001565 is about 404.1271962494.

It can be divided in two parts, 66001 and 565, that added together give a palindrome (66566).

The spelling of 66001565 in words is "sixty-six million, one thousand, five hundred sixty-five".