103999991 has 2 divisors, whose sum is σ = 103999992. Its totient is φ = 103999990.

The previous prime is 103999981. The next prime is 104000011. The reversal of 103999991 is 199999301.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 103999991 - 2¹⁸ = 103737847 is a prime.

It is a Chen prime.

It is equal to p_5978489 and since 103999991 and 5978489 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (103999981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51999995 + 51999996.

It is an arithmetic number, because the mean of its divisors is an integer number (51999996).

Almost surely, 2^103999991 is an apocalyptic number.

103999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

103999991 is an equidigital number, since it uses as much as digits as its factorization.

103999991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 177147, while the sum is 50.

The square root of 103999991 is about 10198.0385859243. The cubic root of 103999991 is about 470.2669239788.

The spelling of 103999991 in words is "one hundred three million, nine hundred ninety-nine thousand, nine hundred ninety-one".