664843443506 has 16 divisors (see below), whose sum is σ = 1087938159840. Its totient is φ = 302198086080.

The previous prime is 664843443499. The next prime is 664843443559. The reversal of 664843443506 is 605344348466.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3595625 + ... + 3776003.

It is an arithmetic number, because the mean of its divisors is an integer number (67996134990).

Almost surely, 2^664843443506 is an apocalyptic number.

664843443506 is a deficient number, since it is larger than the sum of its proper divisors (423094716334).

664843443506 is a wasteful number, since it uses less digits than its factorization.

664843443506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347929.

The product of its (nonzero) digits is 19906560, while the sum is 53.

The spelling of 664843443506 in words is "six hundred sixty-four billion, eight hundred forty-three million, four hundred forty-three thousand, five hundred six".