208741496556321 has 81 divisors (see below), whose sum is σ = 316239523827409. Its totient is φ = 137777727915576.

The previous prime is 208741496556319. The next prime is 208741496556361. The reversal of 208741496556321 is 123655694147802.

It is a happy number.

The square root of 208741496556321 is 14447889.

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

208741496556321 is a `hidden beast` number, since 2 + 0 + 8 + 7 + 4 + 1 + 4 + 9 + 65 + 563 + 2 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 208741496556321 - 2¹ = 208741496556319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208741496556311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 125219853130 + ... + 125219854796.

It is a 1-persistent number, because it is pandigital, but 2⋅208741496556321 = 417482993112642 is not.

Almost surely, 2^{208741496556321} is an apocalyptic number.

208741496556321 is the 14447889-th square number.

208741496556321 is the 7223945-th centered octagonal number.

It is an amenable number.

208741496556321 is a deficient number, since it is larger than the sum of its proper divisors (107498027271088).

208741496556321 is an frugal number, since it uses more digits than its factorization.

208741496556321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3572 (or 1777 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 208741496556321 in words is "two hundred eight trillion, seven hundred forty-one billion, four hundred ninety-six million, five hundred fifty-six thousand, three hundred twenty-one".