28890911 has 4 divisors (see below), whose sum is σ = 33018192. Its totient is φ = 24763632.

The previous prime is 28890907. The next prime is 28890919. The reversal of 28890911 is 11909882.

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 28890911 - 2² = 28890907 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28890919) 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, 2063630 + ... + 2063643.

It is an arithmetic number, because the mean of its divisors is an integer number (8254548).

Almost surely, 2^28890911 is an apocalyptic number.

28890911 is a deficient number, since it is larger than the sum of its proper divisors (4127281).

28890911 is an equidigital number, since it uses as much as digits as its factorization.

28890911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4127280.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 28890911 is about 5375.0266045853. The cubic root of 28890911 is about 306.8459617622.

The spelling of 28890911 in words is "twenty-eight million, eight hundred ninety thousand, nine hundred eleven".