664776332556571 has 4 divisors (see below), whose sum is σ = 664792180605112. Its totient is φ = 664760484508032.

The previous prime is 664776332556533. The next prime is 664776332556577. The reversal of 664776332556571 is 175655233677466.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664776332556571 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664776332556494 and 664776332556503.

It is not an unprimeable number, because it can be changed into a prime (664776332556577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7923961350 + ... + 7924045243.

It is an arithmetic number, because the mean of its divisors is an integer number (166198045151278).

Almost surely, 2^{664776332556571} is an apocalyptic number.

664776332556571 is a deficient number, since it is larger than the sum of its proper divisors (15848048541).

664776332556571 is a wasteful number, since it uses less digits than its factorization.

664776332556571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15848048540.

The product of its digits is 4000752000, while the sum is 73.

The spelling of 664776332556571 in words is "six hundred sixty-four trillion, seven hundred seventy-six billion, three hundred thirty-two million, five hundred fifty-six thousand, five hundred seventy-one".