208921212241 has 81 divisors (see below), whose sum is σ = 271506101979. Its totient is φ = 160248240768.

The previous prime is 208921212229. The next prime is 208921212259. The reversal of 208921212241 is 142212129802.

The square root of 208921212241 is 457079.

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., 162654923025 + 46266289216 = 403305^2 + 215096^2 .

It is not a de Polignac number, because 208921212241 - 2⁹ = 208921211729 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 208921212197 and 208921212206.

It is not an unprimeable number, because it can be changed into a prime (208921212211) by changing a digit.

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 80 ways as a sum of consecutive naturals, for example, 1251025140 + ... + 1251025306.

Almost surely, 2^208921212241 is an apocalyptic number.

208921212241 is the 457079-th square number.

208921212241 is the 228540-th centered octagonal number.

It is an amenable number.

208921212241 is a deficient number, since it is larger than the sum of its proper divisors (62584889738).

208921212241 is an equidigital number, since it uses as much as digits as its factorization.

208921212241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The spelling of 208921212241 in words is "two hundred eight billion, nine hundred twenty-one million, two hundred twelve thousand, two hundred forty-one".