28242091 has 4 divisors (see below), whose sum is σ = 29470032. Its totient is φ = 27014152.

The previous prime is 28242079. The next prime is 28242107. The reversal of 28242091 is 19024282.

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

It is a cyclic number.

It is not a de Polignac number, because 28242091 - 2⁵ = 28242059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28242001) 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, 613936 + ... + 613981.

It is an arithmetic number, because the mean of its divisors is an integer number (7367508).

Almost surely, 2^28242091 is an apocalyptic number.

28242091 is a deficient number, since it is larger than the sum of its proper divisors (1227941).

28242091 is a wasteful number, since it uses less digits than its factorization.

28242091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227940.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 28242091 is about 5314.3288381507. The cubic root of 28242091 is about 304.5315427899.

The spelling of 28242091 in words is "twenty-eight million, two hundred forty-two thousand, ninety-one".