681898457 has 18 divisors (see below), whose sum is σ = 725517198. Its totient is φ = 640814592.

The previous prime is 681898453. The next prime is 681898471. The reversal of 681898457 is 754898186.

681898457 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 96452041 + 585446416 = 9821^2 + 24196^2 .

It is not a de Polignac number, because 681898457 - 2² = 681898453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681898453) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4977293 + ... + 4977429.

It is an arithmetic number, because the mean of its divisors is an integer number (40306511).

Almost surely, 2^681898457 is an apocalyptic number.

It is an amenable number.

681898457 is a deficient number, since it is larger than the sum of its proper divisors (43618741).

681898457 is an equidigital number, since it uses as much as digits as its factorization.

681898457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377 (or 257 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 56.

The square root of 681898457 is about 26113.1855008155. The cubic root of 681898457 is about 880.1835262025.

The spelling of 681898457 in words is "six hundred eighty-one million, eight hundred ninety-eight thousand, four hundred fifty-seven".