28089291 has 4 divisors (see below), whose sum is σ = 37452392. Its totient is φ = 18726192.

The previous prime is 28089241. The next prime is 28089337. The reversal of 28089291 is 19298082.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28089291 - 2¹³ = 28081099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28089241) 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, 4681546 + ... + 4681551.

It is an arithmetic number, because the mean of its divisors is an integer number (9363098).

Almost surely, 2^28089291 is an apocalyptic number.

28089291 is a deficient number, since it is larger than the sum of its proper divisors (9363101).

28089291 is an equidigital number, since it uses as much as digits as its factorization.

28089291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9363100.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 28089291 is about 5299.9331127855. The cubic root of 28089291 is about 303.9813404694.

The spelling of 28089291 in words is "twenty-eight million, eighty-nine thousand, two hundred ninety-one".