209084878564 has 27 divisors (see below), whose sum is σ = 369866498043. Its totient is φ = 103420785408.

The previous prime is 209084878553. The next prime is 209084878601. The reversal of 209084878564 is 465878480902.

The square root of 209084878564 is 457258.

It is a perfect power (a square), and thus also a powerful number.

209084878564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 31102144164 + 177982734400 = 176358^2 + 421880^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 88706874 + ... + 88709230.

Almost surely, 2^209084878564 is an apocalyptic number.

209084878564 is the 457258-th square number.

It is an amenable number.

209084878564 is a deficient number, since it is larger than the sum of its proper divisors (160781619479).

209084878564 is an frugal number, since it uses more digits than its factorization.

209084878564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4912 (or 2456 counting only the distinct ones).

The product of its (nonzero) digits is 30965760, while the sum is 61.

The spelling of 209084878564 in words is "two hundred nine billion, eighty-four million, eight hundred seventy-eight thousand, five hundred sixty-four".