681008137 has 2 divisors, whose sum is σ = 681008138. Its totient is φ = 681008136.

The previous prime is 681008113. The next prime is 681008143. The reversal of 681008137 is 731800186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 344065401 + 336942736 = 18549^2 + 18356^2 .

It is a cyclic number.

It is not a de Polignac number, because 681008137 - 2¹¹ = 681006089 is a prime.

It is not a weakly prime, because it can be changed into another prime (681003137) 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 as a sum of consecutive naturals, namely, 340504068 + 340504069.

It is an arithmetic number, because the mean of its divisors is an integer number (340504069).

Almost surely, 2^681008137 is an apocalyptic number.

It is an amenable number.

681008137 is a deficient number, since it is larger than the sum of its proper divisors (1).

681008137 is an equidigital number, since it uses as much as digits as its factorization.

681008137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 681008137 is about 26096.1326061928. The cubic root of 681008137 is about 879.8002891327.

The spelling of 681008137 in words is "six hundred eighty-one million, eight thousand, one hundred thirty-seven".