209085871122 has 18 divisors (see below), whose sum is σ = 453023590773. Its totient is φ = 69694643712.

The previous prime is 209085871097. The next prime is 209085871129. The reversal of 209085871122 is 221178580902.

It can be written as a sum of positive squares in 2 ways, for example, as 197623813401 + 11462057721 = 444549^2 + 107061^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=323331.

It is not an unprimeable number, because it can be changed into a prime (209085871129) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1886098 + ... + 1993874.

Almost surely, 2^209085871122 is an apocalyptic number.

209085871122 is an abundant number, since it is smaller than the sum of its proper divisors (243937719651).

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

209085871122 is an frugal number, since it uses more digits than its factorization.

209085871122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215562 (or 107782 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 209085871122 in words is "two hundred nine billion, eighty-five million, eight hundred seventy-one thousand, one hundred twenty-two".