681843251 has 4 divisors (see below), whose sum is σ = 694708272. Its totient is φ = 668978232.

The previous prime is 681843247. The next prime is 681843277. The reversal of 681843251 is 152348186.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 681843251 - 2² = 681843247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681843551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6432431 + ... + 6432536.

It is an arithmetic number, because the mean of its divisors is an integer number (173677068).

Almost surely, 2^681843251 is an apocalyptic number.

681843251 is a deficient number, since it is larger than the sum of its proper divisors (12865021).

681843251 is a wasteful number, since it uses less digits than its factorization.

681843251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12865020.

The product of its digits is 46080, while the sum is 38.

The square root of 681843251 is about 26112.1284272271. The cubic root of 681843251 is about 880.1597725568.

The spelling of 681843251 in words is "six hundred eighty-one million, eight hundred forty-three thousand, two hundred fifty-one".