856663120 has 20 divisors (see below), whose sum is σ = 1991741940. Its totient is φ = 342665216.

The previous prime is 856663111. The next prime is 856663141. The reversal of 856663120 is 21366658.

It can be written as a sum of positive squares in 2 ways, for example, as 548871184 + 307791936 = 23428^2 + 17544^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 856663120.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 5354065 + ... + 5354224.

It is an arithmetic number, because the mean of its divisors is an integer number (99587097).

Almost surely, 2^856663120 is an apocalyptic number.

856663120 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

856663120 is an abundant number, since it is smaller than the sum of its proper divisors (1135078820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856663120 is a wasteful number, since it uses less digits than its factorization.

856663120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10708302 (or 10708296 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 856663120 is about 29268.8079702608. The cubic root of 856663120 is about 949.7369982951.

The spelling of 856663120 in words is "eight hundred fifty-six million, six hundred sixty-three thousand, one hundred twenty".