681406820 has 24 divisors (see below), whose sum is σ = 1450559544. Its totient is φ = 268828416.

The previous prime is 681406811. The next prime is 681406829. The reversal of 681406820 is 28604186.

It is an interprime number because it is at equal distance from previous prime (681406811) and next prime (681406829).

It can be written as a sum of positive squares in 4 ways, for example, as 92416 + 681314404 = 304^2 + 26102^2 .

It is not an unprimeable number, because it can be changed into a prime (681406829) 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, 231899 + ... + 234818.

It is an arithmetic number, because the mean of its divisors is an integer number (60439981).

Almost surely, 2^681406820 is an apocalyptic number.

It is an amenable number.

681406820 is an abundant number, since it is smaller than the sum of its proper divisors (769152724).

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

681406820 is a wasteful number, since it uses less digits than its factorization.

681406820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466799 (or 466797 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 681406820 is about 26103.7702257739. The cubic root of 681406820 is about 879.9719429760.

The spelling of 681406820 in words is "six hundred eighty-one million, four hundred six thousand, eight hundred twenty".