208311969 has 4 divisors (see below), whose sum is σ = 277749296. Its totient is φ = 138874644.

The previous prime is 208311923. The next prime is 208312001. The reversal of 208311969 is 969113802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 208311969 - 2¹² = 208307873 is a prime.

It is a super-2 number, since 2×208311969² = 86787752857313922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208311869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34718659 + ... + 34718664.

It is an arithmetic number, because the mean of its divisors is an integer number (69437324).

Almost surely, 2^208311969 is an apocalyptic number.

It is an amenable number.

208311969 is a deficient number, since it is larger than the sum of its proper divisors (69437327).

208311969 is an equidigital number, since it uses as much as digits as its factorization.

208311969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69437326.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 208311969 is about 14433.0166285500. The cubic root of 208311969 is about 592.7952858812.

The spelling of 208311969 in words is "two hundred eight million, three hundred eleven thousand, nine hundred sixty-nine".