28450509991 has 2 divisors, whose sum is σ = 28450509992. Its totient is φ = 28450509990.

The previous prime is 28450509973. The next prime is 28450510009. The reversal of 28450509991 is 19990505482.

It is a balanced prime because it is at equal distance from previous prime (28450509973) and next prime (28450510009).

It is a cyclic number.

It is not a de Polignac number, because 28450509991 - 2¹⁹ = 28449985703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28450509911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14225254995 + 14225254996.

It is an arithmetic number, because the mean of its divisors is an integer number (14225254996).

Almost surely, 2^28450509991 is an apocalyptic number.

28450509991 is a deficient number, since it is larger than the sum of its proper divisors (1).

28450509991 is an equidigital number, since it uses as much as digits as its factorization.

28450509991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1166400, while the sum is 52.

The spelling of 28450509991 in words is "twenty-eight billion, four hundred fifty million, five hundred nine thousand, nine hundred ninety-one".