28969891 has 2 divisors, whose sum is σ = 28969892. Its totient is φ = 28969890.

The previous prime is 28969877. The next prime is 28969901. The reversal of 28969891 is 19896982.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28969891 - 2⁵ = 28969859 is a prime.

It is not a weakly prime, because it can be changed into another prime (28960891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14484945 + 14484946.

It is an arithmetic number, because the mean of its divisors is an integer number (14484946).

Almost surely, 2^28969891 is an apocalyptic number.

28969891 is a deficient number, since it is larger than the sum of its proper divisors (1).

28969891 is an equidigital number, since it uses as much as digits as its factorization.

28969891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 52.

The square root of 28969891 is about 5382.3685306749. The cubic root of 28969891 is about 307.1253188677.

The spelling of 28969891 in words is "twenty-eight million, nine hundred sixty-nine thousand, eight hundred ninety-one".