28768891 has 2 divisors, whose sum is σ = 28768892. Its totient is φ = 28768890.

The previous prime is 28768889. The next prime is 28768897. The reversal of 28768891 is 19886782.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28768891 - 2¹ = 28768889 is a prime.

Together with 28768889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28768897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14384445 + 14384446.

It is an arithmetic number, because the mean of its divisors is an integer number (14384446).

Almost surely, 2^28768891 is an apocalyptic number.

28768891 is a deficient number, since it is larger than the sum of its proper divisors (1).

28768891 is an equidigital number, since it uses as much as digits as its factorization.

28768891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 49.

The square root of 28768891 is about 5363.6639529337. The cubic root of 28768891 is about 306.4133668984.

The spelling of 28768891 in words is "twenty-eight million, seven hundred sixty-eight thousand, eight hundred ninety-one".