856339992818 has 54 divisors (see below), whose sum is σ = 1389451839399. Its totient is φ = 395749065600.

The previous prime is 856339992811. The next prime is 856339992829. The reversal of 856339992818 is 818299933658.

It can be written as a sum of positive squares in 5 ways, for example, as 180338663569 + 676001329249 = 424663^2 + 822193^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=654347.

It is a super-2 number, since 2×856339992818² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856339992811) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1357115363 + ... + 1357115993.

Almost surely, 2^856339992818 is an apocalyptic number.

856339992818 is a deficient number, since it is larger than the sum of its proper divisors (533111846581).

856339992818 is an frugal number, since it uses more digits than its factorization.

856339992818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1420 (or 711 counting only the distinct ones).

The product of its digits is 201553920, while the sum is 71.

The spelling of 856339992818 in words is "eight hundred fifty-six billion, three hundred thirty-nine million, nine hundred ninety-two thousand, eight hundred eighteen".