66665285 has 4 divisors (see below), whose sum is σ = 79998348. Its totient is φ = 53332224.

The previous prime is 66665273. The next prime is 66665311. The reversal of 66665285 is 58256666.

It is a happy number.

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 49084036 + 17581249 = 7006^2 + 4193^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66665285 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, 6666524 + ... + 6666533.

It is an arithmetic number, because the mean of its divisors is an integer number (19999587).

Almost surely, 2^66665285 is an apocalyptic number.

It is an amenable number.

66665285 is a deficient number, since it is larger than the sum of its proper divisors (13333063).

66665285 is a wasteful number, since it uses less digits than its factorization.

66665285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13333062.

The product of its digits is 518400, while the sum is 44.

The square root of 66665285 is about 8164.8811993807. The cubic root of 66665285 is about 405.4773318270.

The spelling of 66665285 in words is "sixty-six million, six hundred sixty-five thousand, two hundred eighty-five".