820647937 has 2 divisors, whose sum is σ = 820647938. Its totient is φ = 820647936.

The previous prime is 820647929. The next prime is 820647977. The reversal of 820647937 is 739746028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 820306881 + 341056 = 28641^2 + 584^2 .

It is a cyclic number.

It is not a de Polignac number, because 820647937 - 2³ = 820647929 is a prime.

It is not a weakly prime, because it can be changed into another prime (820647917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410323968 + 410323969.

It is an arithmetic number, because the mean of its divisors is an integer number (410323969).

Almost surely, 2^820647937 is an apocalyptic number.

It is an amenable number.

820647937 is a deficient number, since it is larger than the sum of its proper divisors (1).

820647937 is an equidigital number, since it uses as much as digits as its factorization.

820647937 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 508032, while the sum is 46.

The square root of 820647937 is about 28646.9533633160. The cubic root of 820647937 is about 936.2366269451.

The spelling of 820647937 in words is "eight hundred twenty million, six hundred forty-seven thousand, nine hundred thirty-seven".