28091291 has 8 divisors (see below), whose sum is σ = 30012480. Its totient is φ = 26214408.

The previous prime is 28091279. The next prime is 28091311. The reversal of 28091291 is 19219082.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28091291 - 2¹⁸ = 27829147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28093291) 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, 9761 + ... + 12306.

It is an arithmetic number, because the mean of its divisors is an integer number (3751560).

Almost surely, 2^28091291 is an apocalyptic number.

28091291 is a deficient number, since it is larger than the sum of its proper divisors (1921189).

28091291 is a wasteful number, since it uses less digits than its factorization.

28091291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22153.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 28091291 is about 5300.1217910535. The cubic root of 28091291 is about 303.9885549419.

It can be divided in two parts, 28091 and 291, that added together give a palindrome (28382).

The spelling of 28091291 in words is "twenty-eight million, ninety-one thousand, two hundred ninety-one".