91123997 has 4 divisors (see below), whose sum is σ = 92008800. Its totient is φ = 90239196.

The previous prime is 91123987. The next prime is 91124069. The reversal of 91123997 is 79932119.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79932119 = 5303 ⋅15073.

It is a cyclic number.

It is not a de Polignac number, because 91123997 - 2¹⁰ = 91122973 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 (91123987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 442247 + ... + 442452.

It is an arithmetic number, because the mean of its divisors is an integer number (23002200).

Almost surely, 2^91123997 is an apocalyptic number.

It is an amenable number.

91123997 is a deficient number, since it is larger than the sum of its proper divisors (884803).

91123997 is a wasteful number, since it uses less digits than its factorization.

91123997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884802.

The product of its digits is 30618, while the sum is 41.

The square root of 91123997 is about 9545.8890104589. The cubic root of 91123997 is about 449.9983489651.

The spelling of 91123997 in words is "ninety-one million, one hundred twenty-three thousand, nine hundred ninety-seven".