664583778368 has 56 divisors (see below), whose sum is σ = 1351934496024. Its totient is φ = 323950694400.

The previous prime is 664583778367. The next prime is 664583778373. The reversal of 664583778368 is 863877385466.

It can be written as a sum of positive squares in 4 ways, for example, as 9079802944 + 655503975424 = 95288^2 + 809632^2 .

It is a super-3 number, since 3×664583778368³ (a number of 36 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (664583778367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3532046 + ... + 3715442.

It is an arithmetic number, because the mean of its divisors is an integer number (24141687429).

Almost surely, 2^664583778368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664583778368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (675967248012).

664583778368 is an abundant number, since it is smaller than the sum of its proper divisors (687350717656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664583778368 is a wasteful number, since it uses less digits than its factorization.

664583778368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184831 (or 184821 counting only the distinct ones).

The product of its digits is 975421440, while the sum is 71.

The spelling of 664583778368 in words is "six hundred sixty-four billion, five hundred eighty-three million, seven hundred seventy-eight thousand, three hundred sixty-eight".