820517405 has 16 divisors (see below), whose sum is σ = 1002685824. Its totient is φ = 644412480.

The previous prime is 820517381. The next prime is 820517407. The reversal of 820517405 is 504715028.

It is not a de Polignac number, because 820517405 - 2⁸ = 820517149 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 (820517407) 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 in 15 ways as a sum of consecutive naturals, for example, 176744 + ... + 181326.

It is an arithmetic number, because the mean of its divisors is an integer number (62667864).

Almost surely, 2^820517405 is an apocalyptic number.

It is an amenable number.

820517405 is a deficient number, since it is larger than the sum of its proper divisors (182168419).

820517405 is a wasteful number, since it uses less digits than its factorization.

820517405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5236.

The product of its (nonzero) digits is 11200, while the sum is 32.

The square root of 820517405 is about 28644.6749850649. The cubic root of 820517405 is about 936.1869851463.

The spelling of 820517405 in words is "eight hundred twenty million, five hundred seventeen thousand, four hundred five".