6855865225209 has 256 divisors, whose sum is σ = 14050842624000. Its totient is φ = 3255545260800.

The previous prime is 6855865225177. The next prime is 6855865225217. The reversal of 6855865225209 is 9025225685586.

6855865225209 is a `hidden beast` number, since 6 + 8 + 5 + 5 + 86 + 5 + 22 + 520 + 9 = 666.

It is not a de Polignac number, because 6855865225209 - 2⁵ = 6855865225177 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (6855865225229) 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 255 ways as a sum of consecutive naturals, for example, 136380139 + ... + 136430399.

It is an arithmetic number, because the mean of its divisors is an integer number (54886104000).

Almost surely, 2^{6855865225209} is an apocalyptic number.

It is an amenable number.

6855865225209 is an abundant number, since it is smaller than the sum of its proper divisors (7194977398791).

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

6855865225209 is a wasteful number, since it uses less digits than its factorization.

6855865225209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50418 (or 50398 counting only the distinct ones).

The product of its (nonzero) digits is 103680000, while the sum is 63.

The spelling of 6855865225209 in words is "six trillion, eight hundred fifty-five billion, eight hundred sixty-five million, two hundred twenty-five thousand, two hundred nine".