681255664 has 20 divisors (see below), whose sum is σ = 1321589520. Its totient is φ = 340200320.

The previous prime is 681255661. The next prime is 681255683. The reversal of 681255664 is 466552186.

It is a self number, because there is not a number n which added to its sum of digits gives 681255664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681255661) 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 3 ways as a sum of consecutive naturals, for example, 13372 + ... + 39259.

It is an arithmetic number, because the mean of its divisors is an integer number (66079476).

Almost surely, 2^681255664 is an apocalyptic number.

It is an amenable number.

681255664 is a deficient number, since it is larger than the sum of its proper divisors (640333856).

681255664 is a wasteful number, since it uses less digits than its factorization.

681255664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53448 (or 53442 counting only the distinct ones).

The product of its digits is 345600, while the sum is 43.

The square root of 681255664 is about 26100.8747746124. The cubic root of 681255664 is about 879.9068703098.

The spelling of 681255664 in words is "six hundred eighty-one million, two hundred fifty-five thousand, six hundred sixty-four".