664615443 has 4 divisors (see below), whose sum is σ = 886153928. Its totient is φ = 443076960.

The previous prime is 664615381. The next prime is 664615463. The reversal of 664615443 is 344516466.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 664615443 - 2⁹ = 664614931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664615463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110769238 + ... + 110769243.

It is an arithmetic number, because the mean of its divisors is an integer number (221538482).

Almost surely, 2^664615443 is an apocalyptic number.

664615443 is a deficient number, since it is larger than the sum of its proper divisors (221538485).

664615443 is a wasteful number, since it uses less digits than its factorization.

664615443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221538484.

The product of its digits is 207360, while the sum is 39.

The square root of 664615443 is about 25780.1365977762. The cubic root of 664615443 is about 872.6835897988.

The spelling of 664615443 in words is "six hundred sixty-four million, six hundred fifteen thousand, four hundred forty-three".