209011723684 has 81 divisors (see below), whose sum is σ = 395196836097. Its totient is φ = 96709605408.

The previous prime is 209011723561. The next prime is 209011723699. The reversal of 209011723684 is 486327110902.

The square root of 209011723684 is 457178.

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

It can be written as a sum of positive squares in only one way, i.e., 150675948900 + 58335774784 = 388170^2 + 241528^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 209011723684.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 920756379 + ... + 920756605.

Almost surely, 2^209011723684 is an apocalyptic number.

209011723684 is the 457178-th square number.

It is an amenable number.

209011723684 is a deficient number, since it is larger than the sum of its proper divisors (186185112413).

209011723684 is an equidigital number, since it uses as much as digits as its factorization.

209011723684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602 (or 301 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 43.

The spelling of 209011723684 in words is "two hundred nine billion, eleven million, seven hundred twenty-three thousand, six hundred eighty-four".