208147811321 has 4 divisors (see below), whose sum is σ = 208160596644. Its totient is φ = 208135026000.

The previous prime is 208147811303. The next prime is 208147811329. The reversal of 208147811321 is 123118741802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 180955801321 + 27192010000 = 425389^2 + 164900^2 .

It is a cyclic number.

It is not a de Polignac number, because 208147811321 - 2¹⁴ = 208147794937 is a prime.

It is a super-2 number, since 2×208147811321² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208147811329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6368210 + ... + 6400811.

It is an arithmetic number, because the mean of its divisors is an integer number (52040149161).

Almost surely, 2^208147811321 is an apocalyptic number.

It is an amenable number.

208147811321 is a deficient number, since it is larger than the sum of its proper divisors (12785323).

208147811321 is a wasteful number, since it uses less digits than its factorization.

208147811321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12785322.

The product of its (nonzero) digits is 21504, while the sum is 38.

The spelling of 208147811321 in words is "two hundred eight billion, one hundred forty-seven million, eight hundred eleven thousand, three hundred twenty-one".