91309445 has 4 divisors (see below), whose sum is σ = 109571340. Its totient is φ = 73047552.

The previous prime is 91309441. The next prime is 91309453. The reversal of 91309445 is 54490319.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54490319 = 13 ⋅4191563.

It can be written as a sum of positive squares in 2 ways, for example, as 9840769 + 81468676 = 3137^2 + 9026^2 .

It is a cyclic number.

It is not a de Polignac number, because 91309445 - 2² = 91309441 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91309441) 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, 9130940 + ... + 9130949.

It is an arithmetic number, because the mean of its divisors is an integer number (27392835).

Almost surely, 2^91309445 is an apocalyptic number.

It is an amenable number.

91309445 is a deficient number, since it is larger than the sum of its proper divisors (18261895).

91309445 is a wasteful number, since it uses less digits than its factorization.

91309445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18261894.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 91309445 is about 9555.5975741970. The cubic root of 91309445 is about 450.3034085522.

The spelling of 91309445 in words is "ninety-one million, three hundred nine thousand, four hundred forty-five".