820865485 has 48 divisors (see below), whose sum is σ = 1169036352. Its totient is φ = 548352000.

The previous prime is 820865483. The next prime is 820865491. The reversal of 820865485 is 584568028.

It is not a de Polignac number, because 820865485 - 2¹ = 820865483 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820865483) 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 47 ways as a sum of consecutive naturals, for example, 682885 + ... + 684085.

It is an arithmetic number, because the mean of its divisors is an integer number (24354924).

Almost surely, 2^820865485 is an apocalyptic number.

820865485 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

820865485 is a deficient number, since it is larger than the sum of its proper divisors (348170867).

820865485 is a wasteful number, since it uses less digits than its factorization.

820865485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294 (or 1277 counting only the distinct ones).

The product of its (nonzero) digits is 614400, while the sum is 46.

The square root of 820865485 is about 28650.7501646990. The cubic root of 820865485 is about 936.3193495522.

It can be divided in two parts, 82086 and 5485, that added together give a triangular number (87571 = T₄₁₈).

The spelling of 820865485 in words is "eight hundred twenty million, eight hundred sixty-five thousand, four hundred eighty-five".