664445071 has 8 divisors (see below), whose sum is σ = 691477920. Its totient is φ = 637687008.

The previous prime is 664445021. The next prime is 664445083. The reversal of 664445071 is 170544466.

664445071 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 664445071 - 2¹¹ = 664443023 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664445071.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664445011) 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, 63756 + ... + 73441.

It is an arithmetic number, because the mean of its divisors is an integer number (86434740).

Almost surely, 2^664445071 is an apocalyptic number.

664445071 is a deficient number, since it is larger than the sum of its proper divisors (27032849).

664445071 is a wasteful number, since it uses less digits than its factorization.

664445071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137393.

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 664445071 is about 25776.8320590409. The cubic root of 664445071 is about 872.6090135625.

It can be divided in two parts, 6644 and 45071, that added together give a palindrome (51715).

The spelling of 664445071 in words is "six hundred sixty-four million, four hundred forty-five thousand, seventy-one".