66671585 has 4 divisors (see below), whose sum is σ = 80005908. Its totient is φ = 53337264.

The previous prime is 66671581. The next prime is 66671587. The reversal of 66671585 is 58517666.

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 17447329 + 49224256 = 4177^2 + 7016^2 .

It is a cyclic number.

It is not a de Polignac number, because 66671585 - 2² = 66671581 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66671581) 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, 6667154 + ... + 6667163.

It is an arithmetic number, because the mean of its divisors is an integer number (20001477).

Almost surely, 2^66671585 is an apocalyptic number.

It is an amenable number.

66671585 is a deficient number, since it is larger than the sum of its proper divisors (13334323).

66671585 is a wasteful number, since it uses less digits than its factorization.

66671585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13334322.

The product of its digits is 302400, while the sum is 44.

The square root of 66671585 is about 8165.2669888988. The cubic root of 66671585 is about 405.4901042253.

The spelling of 66671585 in words is "sixty-six million, six hundred seventy-one thousand, five hundred eighty-five".