664820531771 has 8 divisors (see below), whose sum is σ = 725826716784. Its totient is φ = 603909005920.

The previous prime is 664820531741. The next prime is 664820531849. The reversal of 664820531771 is 177135028466.

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

It is a de Polignac number, because none of the positive numbers 2^k-664820531771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664820531741) 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, 23650100 + ... + 23678193.

It is an arithmetic number, because the mean of its divisors is an integer number (90728339598).

Almost surely, 2^664820531771 is an apocalyptic number.

664820531771 is a deficient number, since it is larger than the sum of its proper divisors (61006185013).

664820531771 is a wasteful number, since it uses less digits than its factorization.

664820531771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47329581.

The product of its (nonzero) digits is 1693440, while the sum is 50.

The spelling of 664820531771 in words is "six hundred sixty-four billion, eight hundred twenty million, five hundred thirty-one thousand, seven hundred seventy-one".