681702876409 has 9 divisors (see below), whose sum is σ = 689522848077. Its totient is φ = 673970636064.

The previous prime is 681702876401. The next prime is 681702876433. The reversal of 681702876409 is 904678207186.

The square root of 681702876409 is 825653.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 133749225 + 681569127184 = 11565^2 + 825572^2 .

It is not a de Polignac number, because 681702876409 - 2³ = 681702876401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681702876401) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 73478479 + ... + 73487755.

Almost surely, 2^681702876409 is an apocalyptic number.

681702876409 is the 825653-rd square number.

681702876409 is the 412827-th centered octagonal number.

It is an amenable number.

681702876409 is a deficient number, since it is larger than the sum of its proper divisors (7819971668).

681702876409 is an frugal number, since it uses more digits than its factorization.

681702876409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18732 (or 9366 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 58.

The spelling of 681702876409 in words is "six hundred eighty-one billion, seven hundred two million, eight hundred seventy-six thousand, four hundred nine".