820609477 has 2 divisors, whose sum is σ = 820609478. Its totient is φ = 820609476.

The previous prime is 820609451. The next prime is 820609507. The reversal of 820609477 is 774906028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 722480641 + 98128836 = 26879^2 + 9906^2 .

It is a cyclic number.

It is not a de Polignac number, because 820609477 - 2¹¹ = 820607429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820609417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410304738 + 410304739.

It is an arithmetic number, because the mean of its divisors is an integer number (410304739).

Almost surely, 2^820609477 is an apocalyptic number.

It is an amenable number.

820609477 is a deficient number, since it is larger than the sum of its proper divisors (1).

820609477 is an equidigital number, since it uses as much as digits as its factorization.

820609477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 820609477 is about 28646.2820798791. The cubic root of 820609477 is about 936.2220010129. Note that the first 3 decimals are identical.

The spelling of 820609477 in words is "eight hundred twenty million, six hundred nine thousand, four hundred seventy-seven".