681679841 has 2 divisors, whose sum is σ = 681679842. Its totient is φ = 681679840.

The previous prime is 681679813. The next prime is 681679879. The reversal of 681679841 is 148976186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 551263441 + 130416400 = 23479^2 + 11420^2 .

It is a cyclic number.

It is not a de Polignac number, because 681679841 - 2¹⁰ = 681678817 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 681679841.

It is not a weakly prime, because it can be changed into another prime (681679241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340839920 + 340839921.

It is an arithmetic number, because the mean of its divisors is an integer number (340839921).

Almost surely, 2^681679841 is an apocalyptic number.

It is an amenable number.

681679841 is a deficient number, since it is larger than the sum of its proper divisors (1).

681679841 is an equidigital number, since it uses as much as digits as its factorization.

681679841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 50.

The square root of 681679841 is about 26108.9992339806. Note that the first 3 decimals coincide. The cubic root of 681679841 is about 880.0894541468.

The spelling of 681679841 in words is "six hundred eighty-one million, six hundred seventy-nine thousand, eight hundred forty-one".