209688894724 has 9 divisors (see below), whose sum is σ = 366957168487. Its totient is φ = 104843989444.

The previous prime is 209688894703. The next prime is 209688894743. The reversal of 209688894724 is 427498886902.

The square root of 209688894724 is 457918.

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

209688894724 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 209688894724.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 801357 + ... + 1030315.

Almost surely, 2^209688894724 is an apocalyptic number.

209688894724 is the 457918-th square number.

It is an amenable number.

209688894724 is a deficient number, since it is larger than the sum of its proper divisors (157268273763).

209688894724 is an frugal number, since it uses more digits than its factorization.

209688894724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457922 (or 228961 counting only the distinct ones).

The product of its (nonzero) digits is 111476736, while the sum is 67.

The spelling of 209688894724 in words is "two hundred nine billion, six hundred eighty-eight million, eight hundred ninety-four thousand, seven hundred twenty-four".