681488491 has 2 divisors, whose sum is σ = 681488492. Its totient is φ = 681488490.

The previous prime is 681488453. The next prime is 681488497. The reversal of 681488491 is 194884186.

681488491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 681488491 - 2⁹ = 681487979 is a prime.

It is not a weakly prime, because it can be changed into another prime (681488497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340744245 + 340744246.

It is an arithmetic number, because the mean of its divisors is an integer number (340744246).

Almost surely, 2^681488491 is an apocalyptic number.

681488491 is a deficient number, since it is larger than the sum of its proper divisors (1).

681488491 is an equidigital number, since it uses as much as digits as its factorization.

681488491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 442368, while the sum is 49.

The square root of 681488491 is about 26105.3345314708. The cubic root of 681488491 is about 880.0070983415.

The spelling of 681488491 in words is "six hundred eighty-one million, four hundred eighty-eight thousand, four hundred ninety-one".