66446665 has 8 divisors (see below), whose sum is σ = 80021448. Its totient is φ = 52967040.

The previous prime is 66446657. The next prime is 66446669. The reversal of 66446665 is 56664466.

It can be written as a sum of positive squares in 4 ways, for example, as 11923209 + 54523456 = 3453^2 + 7384^2 .

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

It is not a de Polignac number, because 66446665 - 2³ = 66446657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66446669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22242 + ... + 25051.

It is an arithmetic number, because the mean of its divisors is an integer number (10002681).

Almost surely, 2^66446665 is an apocalyptic number.

It is an amenable number.

66446665 is a deficient number, since it is larger than the sum of its proper divisors (13574783).

66446665 is a wasteful number, since it uses less digits than its factorization.

66446665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47579.

The product of its digits is 622080, while the sum is 43.

The square root of 66446665 is about 8151.4823805244. The cubic root of 66446665 is about 405.0336099730.

The spelling of 66446665 in words is "sixty-six million, four hundred forty-six thousand, six hundred sixty-five".