208393891 has 2 divisors, whose sum is σ = 208393892. Its totient is φ = 208393890.

The previous prime is 208393831. The next prime is 208393901. The reversal of 208393891 is 198393802.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 208393891 - 2⁹ = 208393379 is a prime.

It is a super-2 number, since 2×208393891² = 86856027612239762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (208393831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104196945 + 104196946.

It is an arithmetic number, because the mean of its divisors is an integer number (104196946).

Almost surely, 2^208393891 is an apocalyptic number.

208393891 is a deficient number, since it is larger than the sum of its proper divisors (1).

208393891 is an equidigital number, since it uses as much as digits as its factorization.

208393891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 208393891 is about 14435.8543564280. The cubic root of 208393891 is about 592.8729844263.

The spelling of 208393891 in words is "two hundred eight million, three hundred ninety-three thousand, eight hundred ninety-one".