91570097 has 4 divisors (see below), whose sum is σ = 93803556. Its totient is φ = 89336640.

The previous prime is 91570069. The next prime is 91570099. The reversal of 91570097 is 79007519.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79007519 = 229 ⋅345011.

It can be written as a sum of positive squares in 2 ways, for example, as 21077281 + 70492816 = 4591^2 + 8396^2 .

It is a cyclic number.

It is not a de Polignac number, because 91570097 - 2¹⁶ = 91504561 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91570097.

It is not an unprimeable number, because it can be changed into a prime (91570099) 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 in 3 ways as a sum of consecutive naturals, for example, 1116668 + ... + 1116749.

It is an arithmetic number, because the mean of its divisors is an integer number (23450889).

Almost surely, 2^91570097 is an apocalyptic number.

It is an amenable number.

91570097 is a deficient number, since it is larger than the sum of its proper divisors (2233459).

91570097 is a wasteful number, since it uses less digits than its factorization.

91570097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2233458.

The product of its (nonzero) digits is 19845, while the sum is 38.

The square root of 91570097 is about 9569.2265622672. The cubic root of 91570097 is about 450.7314802848.

Subtracting from 91570097 its reverse (79007519), we obtain a triangular number (12562578 = T₅₀₁₂).

The spelling of 91570097 in words is "ninety-one million, five hundred seventy thousand, ninety-seven".