91820123 has 2 divisors, whose sum is σ = 91820124. Its totient is φ = 91820122.

The previous prime is 91820087. The next prime is 91820149. The reversal of 91820123 is 32102819.

It is an a-pointer prime, because the next prime (91820149) can be obtained adding 91820123 to its sum of digits (26).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91820123 - 2¹⁰ = 91819099 is a prime.

It is equal to p_5316434 and since 91820123 and 5316434 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 91820092 and 91820101.

It is not a weakly prime, because it can be changed into another prime (91820153) 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 as a sum of consecutive naturals, namely, 45910061 + 45910062.

It is an arithmetic number, because the mean of its divisors is an integer number (45910062).

Almost surely, 2^91820123 is an apocalyptic number.

91820123 is a deficient number, since it is larger than the sum of its proper divisors (1).

91820123 is an equidigital number, since it uses as much as digits as its factorization.

91820123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 91820123 is about 9582.2817220117. The cubic root of 91820123 is about 451.1413381596.

The spelling of 91820123 in words is "ninety-one million, eight hundred twenty thousand, one hundred twenty-three".