849721 has 2 divisors, whose sum is σ = 849722. Its totient is φ = 849720.

The previous prime is 849703. The next prime is 849727. The reversal of 849721 is 127948.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 541696 + 308025 = 736^2 + 555^2 .

It is a cyclic number.

It is not a de Polignac number, because 849721 - 2⁷ = 849593 is a prime.

It is not a weakly prime, because it can be changed into another prime (849727) 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, 424860 + 424861.

It is an arithmetic number, because the mean of its divisors is an integer number (424861).

2⁸⁴⁹⁷²¹ is an apocalyptic number.

It is an amenable number.

849721 is a deficient number, since it is larger than the sum of its proper divisors (1).

849721 is an equidigital number, since it uses as much as digits as its factorization.

849721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 31.

The square root of 849721 is about 921.8031243167. The cubic root of 849721 is about 94.7164583555.

It can be divided in two parts, 8 and 49721, that added together give a square (49729 = 223²).

The spelling of 849721 in words is "eight hundred forty-nine thousand, seven hundred twenty-one".