681968457 has 16 divisors (see below), whose sum is σ = 1034967360. Its totient is φ = 443556000.

The previous prime is 681968453. The next prime is 681968467. The reversal of 681968457 is 754869186.

It is not a de Polignac number, because 681968457 - 2² = 681968453 is a prime.

It is not an unprimeable number, because it can be changed into a prime (681968453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 306919 + ... + 309132.

It is an arithmetic number, because the mean of its divisors is an integer number (64685460).

Almost surely, 2^681968457 is an apocalyptic number.

It is an amenable number.

681968457 is a deficient number, since it is larger than the sum of its proper divisors (352998903).

681968457 is a wasteful number, since it uses less digits than its factorization.

681968457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616101 (or 616095 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The square root of 681968457 is about 26114.5257854704. The cubic root of 681968457 is about 880.2136434622.

The spelling of 681968457 in words is "six hundred eighty-one million, nine hundred sixty-eight thousand, four hundred fifty-seven".