91749505 has 4 divisors (see below), whose sum is σ = 110099412. Its totient is φ = 73399600.

The previous prime is 91749503. The next prime is 91749509. The reversal of 91749505 is 50594719.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50594719 = 7 ⋅7227817.

It can be written as a sum of positive squares in 2 ways, for example, as 35093776 + 56655729 = 5924^2 + 7527^2 .

It is not a de Polignac number, because 91749505 - 2¹ = 91749503 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91749503) 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, 9174946 + ... + 9174955.

It is an arithmetic number, because the mean of its divisors is an integer number (27524853).

Almost surely, 2^91749505 is an apocalyptic number.

It is an amenable number.

91749505 is a deficient number, since it is larger than the sum of its proper divisors (18349907).

91749505 is a wasteful number, since it uses less digits than its factorization.

91749505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18349906.

The product of its (nonzero) digits is 56700, while the sum is 40.

The square root of 91749505 is about 9578.5961915095. The cubic root of 91749505 is about 451.0256522988.

The spelling of 91749505 in words is "ninety-one million, seven hundred forty-nine thousand, five hundred five".