664784840864 has 24 divisors (see below), whose sum is σ = 1308925875348. Its totient is φ = 332359221760.

The previous prime is 664784840861. The next prime is 664784840873. The reversal of 664784840864 is 468048487466.

It can be written as a sum of positive squares in 2 ways, for example, as 651100520464 + 13684320400 = 806908^2 + 116980^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 664784840864.

It is not an unprimeable number, because it can be changed into a prime (664784840861) 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, 710477 + ... + 1354380.

Almost surely, 2^664784840864 is an apocalyptic number.

It is an amenable number.

664784840864 is a deficient number, since it is larger than the sum of its proper divisors (644141034484).

664784840864 is a wasteful number, since it uses less digits than its factorization.

664784840864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2074928 (or 2074920 counting only the distinct ones).

The product of its (nonzero) digits is 198180864, while the sum is 65.

The spelling of 664784840864 in words is "six hundred sixty-four billion, seven hundred eighty-four million, eight hundred forty thousand, eight hundred sixty-four".