91288239 has 8 divisors (see below), whose sum is σ = 139105920. Its totient is φ = 52164696.

The previous prime is 91288229. The next prime is 91288289. The reversal of 91288239 is 93288219.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91288239 - 2²⁴ = 74511023 is a prime.

It is a super-2 number, since 2×91288239² = 16667085159442242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 91288239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91288229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2173509 + ... + 2173550.

It is an arithmetic number, because the mean of its divisors is an integer number (17388240).

Almost surely, 2^91288239 is an apocalyptic number.

91288239 is a deficient number, since it is larger than the sum of its proper divisors (47817681).

91288239 is a wasteful number, since it uses less digits than its factorization.

91288239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4347069.

The product of its digits is 62208, while the sum is 42.

The square root of 91288239 is about 9554.4878983648. The cubic root of 91288239 is about 450.2685458812.

The spelling of 91288239 in words is "ninety-one million, two hundred eighty-eight thousand, two hundred thirty-nine".