91288559 has 4 divisors (see below), whose sum is σ = 96093240. Its totient is φ = 86483880.

The previous prime is 91288537. The next prime is 91288579. The reversal of 91288559 is 95588219.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95588219 = 2029 ⋅47111.

It is a cyclic number.

It is not a de Polignac number, because 91288559 - 2¹² = 91284463 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 (91288579) 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, 2402312 + ... + 2402349.

It is an arithmetic number, because the mean of its divisors is an integer number (24023310).

Almost surely, 2^91288559 is an apocalyptic number.

91288559 is a deficient number, since it is larger than the sum of its proper divisors (4804681).

91288559 is a wasteful number, since it uses less digits than its factorization.

91288559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4804680.

The product of its digits is 259200, while the sum is 47.

The square root of 91288559 is about 9554.5046444073. The cubic root of 91288559 is about 450.2690720014.

The spelling of 91288559 in words is "ninety-one million, two hundred eighty-eight thousand, five hundred fifty-nine".