28309451 has 2 divisors, whose sum is σ = 28309452. Its totient is φ = 28309450.

The previous prime is 28309409. The next prime is 28309453. The reversal of 28309451 is 15490382.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28309451 - 2¹⁸ = 28047307 is a prime.

Together with 28309453, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28309453) 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, 14154725 + 14154726.

It is an arithmetic number, because the mean of its divisors is an integer number (14154726).

Almost surely, 2^28309451 is an apocalyptic number.

28309451 is a deficient number, since it is larger than the sum of its proper divisors (1).

28309451 is an equidigital number, since it uses as much as digits as its factorization.

28309451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 28309451 is about 5320.6626467011. The cubic root of 28309451 is about 304.7734625263.

The spelling of 28309451 in words is "twenty-eight million, three hundred nine thousand, four hundred fifty-one".