681031636 has 12 divisors (see below), whose sum is σ = 1194871860. Its totient is φ = 339639680.

The previous prime is 681031597. The next prime is 681031639. The reversal of 681031636 is 636130186.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 90250000 + 590781636 = 9500^2 + 24306^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681031639) 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 3 ways as a sum of consecutive naturals, for example, 217285 + ... + 220396.

It is an arithmetic number, because the mean of its divisors is an integer number (99572655).

Almost surely, 2^681031636 is an apocalyptic number.

It is an amenable number.

681031636 is a deficient number, since it is larger than the sum of its proper divisors (513840224).

681031636 is a wasteful number, since it uses less digits than its factorization.

681031636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438074 (or 438072 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 681031636 is about 26096.5828414373. The cubic root of 681031636 is about 879.8104085366.

The spelling of 681031636 in words is "six hundred eighty-one million, thirty-one thousand, six hundred thirty-six".