28219091 has 8 divisors (see below), whose sum is σ = 29509920. Its totient is φ = 26933632.

The previous prime is 28219073. The next prime is 28219153. The reversal of 28219091 is 19091282.

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 a de Polignac number, because none of the positive numbers 2^k-28219091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28213091) 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, 12605 + ... + 14673.

It is an arithmetic number, because the mean of its divisors is an integer number (3688740).

Almost surely, 2^28219091 is an apocalyptic number.

28219091 is a deficient number, since it is larger than the sum of its proper divisors (1290829).

28219091 is a wasteful number, since it uses less digits than its factorization.

28219091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2685.

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

The square root of 28219091 is about 5312.1644364609. The cubic root of 28219091 is about 304.4488514654.

The spelling of 28219091 in words is "twenty-eight million, two hundred nineteen thousand, ninety-one".