681305120660 has 24 divisors (see below), whose sum is σ = 1430889009480. Its totient is φ = 272493809024.

The previous prime is 681305120659. The next prime is 681305120663. The reversal of 681305120660 is 66021503186.

It can be written as a sum of positive squares in 4 ways, for example, as 316039606276 + 365265514384 = 562174^2 + 604372^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681305120663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1566575 + ... + 1953654.

It is an arithmetic number, because the mean of its divisors is an integer number (59620375395).

Almost surely, 2^681305120660 is an apocalyptic number.

It is an amenable number.

681305120660 is an abundant number, since it is smaller than the sum of its proper divisors (749583888820).

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

681305120660 is a wasteful number, since it uses less digits than its factorization.

681305120660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3529915 (or 3529913 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 38.

The spelling of 681305120660 in words is "six hundred eighty-one billion, three hundred five million, one hundred twenty thousand, six hundred sixty".