91187123 has 2 divisors, whose sum is σ = 91187124. Its totient is φ = 91187122.

The previous prime is 91187087. The next prime is 91187141. The reversal of 91187123 is 32178119.

It is a strong prime.

It is an emirp because it is prime and its reverse (32178119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91187123 - 2¹⁸ = 90924979 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91187123.

It is not a weakly prime, because it can be changed into another prime (91187323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45593561 + 45593562.

It is an arithmetic number, because the mean of its divisors is an integer number (45593562).

Almost surely, 2^91187123 is an apocalyptic number.

91187123 is a deficient number, since it is larger than the sum of its proper divisors (1).

91187123 is an equidigital number, since it uses as much as digits as its factorization.

91187123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 91187123 is about 9549.1948875285. The cubic root of 91187123 is about 450.1022368530.

The spelling of 91187123 in words is "ninety-one million, one hundred eighty-seven thousand, one hundred twenty-three".