66857585 has 4 divisors (see below), whose sum is σ = 80229108. Its totient is φ = 53486064.

The previous prime is 66857537. The next prime is 66857587. The reversal of 66857585 is 58575866.

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 24880144 + 41977441 = 4988^2 + 6479^2 .

It is a cyclic number.

It is not a de Polignac number, because 66857585 - 2⁶ = 66857521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66857587) 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, 6685754 + ... + 6685763.

It is an arithmetic number, because the mean of its divisors is an integer number (20057277).

Almost surely, 2^66857585 is an apocalyptic number.

It is an amenable number.

66857585 is a deficient number, since it is larger than the sum of its proper divisors (13371523).

66857585 is a wasteful number, since it uses less digits than its factorization.

66857585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13371522.

The product of its digits is 2016000, while the sum is 50.

The square root of 66857585 is about 8176.6487633993. The cubic root of 66857585 is about 405.8668320891.

The spelling of 66857585 in words is "sixty-six million, eight hundred fifty-seven thousand, five hundred eighty-five".