208628669 has 4 divisors (see below), whose sum is σ = 210151644. Its totient is φ = 207105696.

The previous prime is 208628633. The next prime is 208628677. The reversal of 208628669 is 966826802.

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 183277444 + 25351225 = 13538^2 + 5035^2 .

It is a cyclic number.

It is not a de Polignac number, because 208628669 - 2¹² = 208624573 is a prime.

It is a super-2 number, since 2×208628669² = 87051843057423122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208622669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 761282 + ... + 761555.

It is an arithmetic number, because the mean of its divisors is an integer number (52537911).

Almost surely, 2^208628669 is an apocalyptic number.

It is an amenable number.

208628669 is a deficient number, since it is larger than the sum of its proper divisors (1522975).

208628669 is a wasteful number, since it uses less digits than its factorization.

208628669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522974.

The product of its (nonzero) digits is 497664, while the sum is 47.

The square root of 208628669 is about 14443.9838341089. The cubic root of 208628669 is about 593.0955458034.

The spelling of 208628669 in words is "two hundred eight million, six hundred twenty-eight thousand, six hundred sixty-nine".