851310209 has 4 divisors (see below), whose sum is σ = 853592916. Its totient is φ = 849027504.

The previous prime is 851310197. The next prime is 851310211. The reversal of 851310209 is 902013158.

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

It can be written as a sum of positive squares in 2 ways, for example, as 322310209 + 529000000 = 17953^2 + 23000^2 .

It is a cyclic number.

It is not a de Polignac number, because 851310209 - 2¹⁶ = 851244673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (851310289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1140794 + ... + 1141539.

It is an arithmetic number, because the mean of its divisors is an integer number (213398229).

Almost surely, 2^851310209 is an apocalyptic number.

It is an amenable number.

851310209 is a deficient number, since it is larger than the sum of its proper divisors (2282707).

851310209 is a wasteful number, since it uses less digits than its factorization.

851310209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2282706.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 851310209 is about 29177.2207209666. The cubic root of 851310209 is about 947.7547008012.

The spelling of 851310209 in words is "eight hundred fifty-one million, three hundred ten thousand, two hundred nine".