209621128336 has 45 divisors (see below), whose sum is σ = 431500998891. Its totient is φ = 98630585856.

The previous prime is 209621128307. The next prime is 209621128351. The reversal of 209621128336 is 633821126902.

The square root of 209621128336 is 457844.

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

209621128336 is digitally balanced in base 3, 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 149889768336 + 59731360000 = 387156^2 + 244400^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 209621128292 and 209621128301.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 31130026 + ... + 31136758.

Almost surely, 2^209621128336 is an apocalyptic number.

209621128336 is the 457844-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209621128336

209621128336 is an abundant number, since it is smaller than the sum of its proper divisors (221879870555).

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

209621128336 is an frugal number, since it uses more digits than its factorization.

209621128336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13508 (or 6752 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The spelling of 209621128336 in words is "two hundred nine billion, six hundred twenty-one million, one hundred twenty-eight thousand, three hundred thirty-six".