66000665 has 8 divisors (see below), whose sum is σ = 81932040. Its totient is φ = 50979712.

The previous prime is 66000659. The next prime is 66000673. The reversal of 66000665 is 56600066.

It can be written as a sum of positive squares in 4 ways, for example, as 8042896 + 57957769 = 2836^2 + 7613^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66000665 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

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, 227444 + ... + 227733.

It is an arithmetic number, because the mean of its divisors is an integer number (10241505).

Almost surely, 2^66000665 is an apocalyptic number.

It is an amenable number.

66000665 is a deficient number, since it is larger than the sum of its proper divisors (15931375).

66000665 is a wasteful number, since it uses less digits than its factorization.

66000665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455211.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 66000665 is about 8124.0793324536. The cubic root of 66000665 is about 404.1253593428.

The spelling of 66000665 in words is "sixty-six million, six hundred sixty-five", and thus it is an aban number.