820575137 has 2 divisors, whose sum is σ = 820575138. Its totient is φ = 820575136.

The previous prime is 820575121. The next prime is 820575143. The reversal of 820575137 is 731575028.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 665846416 + 154728721 = 25804^2 + 12439^2 .

It is a cyclic number.

It is not a de Polignac number, because 820575137 - 2⁴ = 820575121 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 820575137.

It is not a weakly prime, because it can be changed into another prime (820574137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410287568 + 410287569.

It is an arithmetic number, because the mean of its divisors is an integer number (410287569).

Almost surely, 2^820575137 is an apocalyptic number.

It is an amenable number.

820575137 is a deficient number, since it is larger than the sum of its proper divisors (1).

820575137 is an equidigital number, since it uses as much as digits as its factorization.

820575137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58800, while the sum is 38.

The square root of 820575137 is about 28645.6826939069. The cubic root of 820575137 is about 936.2089414871.

The spelling of 820575137 in words is "eight hundred twenty million, five hundred seventy-five thousand, one hundred thirty-seven".