851952209 has 2 divisors, whose sum is σ = 851952210. Its totient is φ = 851952208.

The previous prime is 851952139. The next prime is 851952259. The reversal of 851952209 is 902259158.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 823862209 + 28090000 = 28703^2 + 5300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-851952209 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (851952259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425976104 + 425976105.

It is an arithmetic number, because the mean of its divisors is an integer number (425976105).

Almost surely, 2^851952209 is an apocalyptic number.

It is an amenable number.

851952209 is a deficient number, since it is larger than the sum of its proper divisors (1).

851952209 is an equidigital number, since it uses as much as digits as its factorization.

851952209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 41.

The square root of 851952209 is about 29188.2203808317. The cubic root of 851952209 is about 947.9928848861.

The spelling of 851952209 in words is "eight hundred fifty-one million, nine hundred fifty-two thousand, two hundred nine".