664541663 has 4 divisors (see below), whose sum is σ = 699517560. Its totient is φ = 629565768.

The previous prime is 664541659. The next prime is 664541671. The reversal of 664541663 is 366145466.

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

It is a cyclic number.

It is not a de Polignac number, because 664541663 - 2² = 664541659 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 664541663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664541623) 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, 17487920 + ... + 17487957.

It is an arithmetic number, because the mean of its divisors is an integer number (174879390).

Almost surely, 2^664541663 is an apocalyptic number.

664541663 is a deficient number, since it is larger than the sum of its proper divisors (34975897).

664541663 is a wasteful number, since it uses less digits than its factorization.

664541663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34975896.

The product of its digits is 311040, while the sum is 41.

The square root of 664541663 is about 25778.7056114150. The cubic root of 664541663 is about 872.6512959470.

The spelling of 664541663 in words is "six hundred sixty-four million, five hundred forty-one thousand, six hundred sixty-three".