856559318401 has 4 divisors (see below), whose sum is σ = 856561169412. Its totient is φ = 856557467392.

The previous prime is 856559318393. The next prime is 856559318453. The reversal of 856559318401 is 104813955658.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 436655318401 + 419904000000 = 660799^2 + 648000^2 .

It is a cyclic number.

It is not a de Polignac number, because 856559318401 - 2³ = 856559318393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856559358401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 462105 + ... + 1388041.

It is an arithmetic number, because the mean of its divisors is an integer number (214140292353).

Almost surely, 2^856559318401 is an apocalyptic number.

It is an amenable number.

856559318401 is a deficient number, since it is larger than the sum of its proper divisors (1851011).

856559318401 is an equidigital number, since it uses as much as digits as its factorization.

856559318401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851010.

The product of its (nonzero) digits is 5184000, while the sum is 55.

The spelling of 856559318401 in words is "eight hundred fifty-six billion, five hundred fifty-nine million, three hundred eighteen thousand, four hundred one".