28610891 has 4 divisors (see below), whose sum is σ = 29079984. Its totient is φ = 28141800.

The previous prime is 28610887. The next prime is 28610893. The reversal of 28610891 is 19801682.

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 28610891 - 2² = 28610887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28610893) 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, 234455 + ... + 234576.

It is an arithmetic number, because the mean of its divisors is an integer number (7269996).

Almost surely, 2^28610891 is an apocalyptic number.

28610891 is a deficient number, since it is larger than the sum of its proper divisors (469093).

28610891 is an equidigital number, since it uses as much as digits as its factorization.

28610891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469092.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 28610891 is about 5348.9149366951. The cubic root of 28610891 is about 305.8513916648.

The spelling of 28610891 in words is "twenty-eight million, six hundred ten thousand, eight hundred ninety-one".