66135665 has 8 divisors (see below), whose sum is σ = 81298728. Its totient is φ = 51617920.

The previous prime is 66135659. The next prime is 66135673. The reversal of 66135665 is 56653166.

It can be written as a sum of positive squares in 4 ways, for example, as 6241 + 66129424 = 79^2 + 8132^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66135665 - 2¹⁴ = 66119281 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161102 + ... + 161511.

It is an arithmetic number, because the mean of its divisors is an integer number (10162341).

Almost surely, 2^66135665 is an apocalyptic number.

It is an amenable number.

66135665 is a deficient number, since it is larger than the sum of its proper divisors (15163063).

66135665 is a wasteful number, since it uses less digits than its factorization.

66135665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322659.

The product of its digits is 97200, while the sum is 38.

The square root of 66135665 is about 8132.3837218862. The cubic root of 66135665 is about 404.4007089331.

The spelling of 66135665 in words is "sixty-six million, one hundred thirty-five thousand, six hundred sixty-five".