820920565 has 16 divisors (see below), whose sum is σ = 1065249792. Its totient is φ = 604950784.

The previous prime is 820920563. The next prime is 820920637. The reversal of 820920565 is 565029028.

It is a happy number.

820920565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 820920565 - 2¹ = 820920563 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 (820920563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98749 + ... + 106738.

It is an arithmetic number, because the mean of its divisors is an integer number (66578112).

Almost surely, 2^820920565 is an apocalyptic number.

820920565 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

820920565 is a deficient number, since it is larger than the sum of its proper divisors (244329227).

820920565 is a wasteful number, since it uses less digits than its factorization.

820920565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205556.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 820920565 is about 28651.7113799508. The cubic root of 820920565 is about 936.3402913985.

The spelling of 820920565 in words is "eight hundred twenty million, nine hundred twenty thousand, five hundred sixty-five".