681251 has 2 divisors, whose sum is σ = 681252. Its totient is φ = 681250.

The previous prime is 681229. The next prime is 681253. The reversal of 681251 is 152186.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681251 is a prime.

Together with 681253, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₅₅₁₅₇ and since 681251 and 55157 have the same sum of digits, it is a Honaker prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681251.

It is not a weakly prime, because it can be changed into another prime (681253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340625 + 340626.

It is an arithmetic number, because the mean of its divisors is an integer number (340626).

2⁶⁸¹²⁵¹ is an apocalyptic number.

681251 is a deficient number, since it is larger than the sum of its proper divisors (1).

681251 is an equidigital number, since it uses as much as digits as its factorization.

681251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 23.

The square root of 681251 is about 825.3793067433. The cubic root of 681251 is about 87.9904862304.

The spelling of 681251 in words is "six hundred eighty-one thousand, two hundred fifty-one".