28449991 has 2 divisors, whose sum is σ = 28449992. Its totient is φ = 28449990.

The previous prime is 28449989. The next prime is 28450001. The reversal of 28449991 is 19994482.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28449991 - 2¹ = 28449989 is a prime.

Together with 28449989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28449931) 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, 14224995 + 14224996.

It is an arithmetic number, because the mean of its divisors is an integer number (14224996).

Almost surely, 2^28449991 is an apocalyptic number.

28449991 is a deficient number, since it is larger than the sum of its proper divisors (1).

28449991 is an equidigital number, since it uses as much as digits as its factorization.

28449991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 46.

The square root of 28449991 is about 5333.8532975702. The cubic root of 28449991 is about 305.2769713741.

The spelling of 28449991 in words is "twenty-eight million, four hundred forty-nine thousand, nine hundred ninety-one".