851749 has 2 divisors, whose sum is σ = 851750. Its totient is φ = 851748.

The previous prime is 851731. The next prime is 851761. The reversal of 851749 is 947158.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 842724 + 9025 = 918^2 + 95^2 .

It is a cyclic number.

It is not a de Polignac number, because 851749 - 2¹¹ = 849701 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (851449) 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, 425874 + 425875.

It is an arithmetic number, because the mean of its divisors is an integer number (425875).

2⁸⁵¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

851749 is a deficient number, since it is larger than the sum of its proper divisors (1).

851749 is an equidigital number, since it uses as much as digits as its factorization.

851749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 34.

The square root of 851749 is about 922.9024867233. The cubic root of 851749 is about 94.7917506634.

It can be divided in two parts, 851 and 749, that added together give a square (1600 = 40²).

The spelling of 851749 in words is "eight hundred fifty-one thousand, seven hundred forty-nine".