664181056 has 56 divisors (see below), whose sum is σ = 1643213376. Its totient is φ = 258769920.

The previous prime is 664181039. The next prime is 664181057. The reversal of 664181056 is 650181466.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-2 number, since 2×664181056² = 882272950298550272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664181057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62461 + ... + 72316.

It is an arithmetic number, because the mean of its divisors is an integer number (29343096).

Almost surely, 2^664181056 is an apocalyptic number.

It is an amenable number.

664181056 is an abundant number, since it is smaller than the sum of its proper divisors (979032320).

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

664181056 is a wasteful number, since it uses less digits than its factorization.

664181056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134807 (or 134797 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 664181056 is about 25771.7103817345. The cubic root of 664181056 is about 872.4934221719.

The spelling of 664181056 in words is "six hundred sixty-four million, one hundred eighty-one thousand, fifty-six".