681599851 has 2 divisors, whose sum is σ = 681599852. Its totient is φ = 681599850.

The previous prime is 681599839. The next prime is 681599857. The reversal of 681599851 is 158995186.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 681599851 - 2¹⁷ = 681468779 is a prime.

It is not a weakly prime, because it can be changed into another prime (681599857) 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, 340799925 + 340799926.

It is an arithmetic number, because the mean of its divisors is an integer number (340799926).

Almost surely, 2^681599851 is an apocalyptic number.

681599851 is a deficient number, since it is larger than the sum of its proper divisors (1).

681599851 is an equidigital number, since it uses as much as digits as its factorization.

681599851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 777600, while the sum is 52.

The square root of 681599851 is about 26107.4673417396. The cubic root of 681599851 is about 880.0550288419.

The spelling of 681599851 in words is "six hundred eighty-one million, five hundred ninety-nine thousand, eight hundred fifty-one".