208223999 has 4 divisors (see below), whose sum is σ = 208266936. Its totient is φ = 208181064.

The previous prime is 208223989. The next prime is 208224001. The reversal of 208223999 is 999322802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999322802 = 2 ⋅499661401.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208223999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208223929) 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, 13109 + ... + 24254.

It is an arithmetic number, because the mean of its divisors is an integer number (52066734).

Almost surely, 2^208223999 is an apocalyptic number.

208223999 is a deficient number, since it is larger than the sum of its proper divisors (42937).

208223999 is an equidigital number, since it uses as much as digits as its factorization.

208223999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42936.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 208223999 is about 14429.9687802850. The cubic root of 208223999 is about 592.7118284527.

The spelling of 208223999 in words is "two hundred eight million, two hundred twenty-three thousand, nine hundred ninety-nine".