851761 has 2 divisors, whose sum is σ = 851762. Its totient is φ = 851760.

The previous prime is 851749. The next prime is 851797. The reversal of 851761 is 167158.

It is a happy number.

851761 is nontrivially palindromic in base 9.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 732736 + 119025 = 856^2 + 345^2 .

It is a cyclic number.

It is not a de Polignac number, because 851761 - 2⁷ = 851633 is a prime.

It is a super-2 number, since 2×851761² = 1450993602242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (851731) 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, 425880 + 425881.

It is an arithmetic number, because the mean of its divisors is an integer number (425881).

2⁸⁵¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

851761 is a deficient number, since it is larger than the sum of its proper divisors (1).

851761 is an equidigital number, since it uses as much as digits as its factorization.

851761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 28.

The square root of 851761 is about 922.9089879289. The cubic root of 851761 is about 94.7921958242.

The spelling of 851761 in words is "eight hundred fifty-one thousand, seven hundred sixty-one".