28880191 has 4 divisors (see below), whose sum is σ = 28907032. Its totient is φ = 28853352.

The previous prime is 28880183. The next prime is 28880213. The reversal of 28880191 is 19108882.

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 28880191 - 2³ = 28880183 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28880191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28883191) 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, 11736 + ... + 13981.

It is an arithmetic number, because the mean of its divisors is an integer number (7226758).

Almost surely, 2^28880191 is an apocalyptic number.

28880191 is a deficient number, since it is larger than the sum of its proper divisors (26841).

28880191 is a wasteful number, since it uses less digits than its factorization.

28880191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26840.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 28880191 is about 5374.0293076983. The cubic root of 28880191 is about 306.8080052386.

The spelling of 28880191 in words is "twenty-eight million, eight hundred eighty thousand, one hundred ninety-one".