820027909 has 2 divisors, whose sum is σ = 820027910. Its totient is φ = 820027908.

The previous prime is 820027853. The next prime is 820028021. The reversal of 820027909 is 909720028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 446688225 + 373339684 = 21135^2 + 19322^2 .

It is a cyclic number.

It is not a de Polignac number, because 820027909 - 2²⁹ = 283156997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820027009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410013954 + 410013955.

It is an arithmetic number, because the mean of its divisors is an integer number (410013955).

Almost surely, 2^820027909 is an apocalyptic number.

It is an amenable number.

820027909 is a deficient number, since it is larger than the sum of its proper divisors (1).

820027909 is an equidigital number, since it uses as much as digits as its factorization.

820027909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 820027909 is about 28636.1294346844. The cubic root of 820027909 is about 936.0007811162. Note that the first 3 decimals are identical.

The spelling of 820027909 in words is "eight hundred twenty million, twenty-seven thousand, nine hundred nine".