66012665 has 8 divisors (see below), whose sum is σ = 81147528. Its totient is φ = 51521920.

The previous prime is 66012647. The next prime is 66012743. The reversal of 66012665 is 56621066.

It can be written as a sum of positive squares in 4 ways, for example, as 4343056 + 61669609 = 2084^2 + 7853^2 .

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

It is not a de Polignac number, because 66012665 - 2⁶ = 66012601 is a prime.

It is a Curzon 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, 160802 + ... + 161211.

It is an arithmetic number, because the mean of its divisors is an integer number (10143441).

Almost surely, 2^66012665 is an apocalyptic number.

It is an amenable number.

66012665 is a deficient number, since it is larger than the sum of its proper divisors (15134863).

66012665 is a wasteful number, since it uses less digits than its factorization.

66012665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322059.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 66012665 is about 8124.8178441120. The cubic root of 66012665 is about 404.1498500579.

The spelling of 66012665 in words is "sixty-six million, twelve thousand, six hundred sixty-five".