820307897 has 6 divisors (see below), whose sum is σ = 821983134. Its totient is φ = 818635520.

The previous prime is 820307879. The next prime is 820307899. The reversal of 820307897 is 798703028.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 4405801 + 815902096 = 2099^2 + 28564^2 .

It is not a de Polignac number, because 820307897 - 2²⁰ = 819259321 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820307899) 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 5 ways as a sum of consecutive naturals, for example, 673433 + ... + 674649.

It is an arithmetic number, because the mean of its divisors is an integer number (136997189).

Almost surely, 2^820307897 is an apocalyptic number.

It is an amenable number.

820307897 is a deficient number, since it is larger than the sum of its proper divisors (1675237).

820307897 is an frugal number, since it uses more digits than its factorization.

820307897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2859 (or 2038 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 44.

The square root of 820307897 is about 28641.0177368054. The cubic root of 820307897 is about 936.1072974769.

The spelling of 820307897 in words is "eight hundred twenty million, three hundred seven thousand, eight hundred ninety-seven".