681859816 has 16 divisors (see below), whose sum is σ = 1394713440. Its totient is φ = 309936240.

The previous prime is 681859813. The next prime is 681859819. The reversal of 681859816 is 618958186.

It is an interprime number because it is at equal distance from previous prime (681859813) and next prime (681859819).

It is not an unprimeable number, because it can be changed into a prime (681859811) 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, 3874116 + ... + 3874291.

It is an arithmetic number, because the mean of its divisors is an integer number (87169590).

Almost surely, 2^681859816 is an apocalyptic number.

It is an amenable number.

681859816 is an abundant number, since it is smaller than the sum of its proper divisors (712853624).

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

681859816 is a wasteful number, since it uses less digits than its factorization.

681859816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7748424 (or 7748420 counting only the distinct ones).

The product of its digits is 829440, while the sum is 52.

The square root of 681859816 is about 26112.4456150702. The cubic root of 681859816 is about 880.1669001620.

The spelling of 681859816 in words is "six hundred eighty-one million, eight hundred fifty-nine thousand, eight hundred sixteen".