28729447 has 2 divisors, whose sum is σ = 28729448. Its totient is φ = 28729446.

The previous prime is 28729433. The next prime is 28729451. The reversal of 28729447 is 74492782.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28729447 - 2⁷ = 28729319 is a prime.

It is a super-2 number, since 2×28729447² = 1650762249851618, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28729417) 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, 14364723 + 14364724.

It is an arithmetic number, because the mean of its divisors is an integer number (14364724).

Almost surely, 2^28729447 is an apocalyptic number.

28729447 is a deficient number, since it is larger than the sum of its proper divisors (1).

28729447 is an equidigital number, since it uses as much as digits as its factorization.

28729447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 225792, while the sum is 43.

The square root of 28729447 is about 5359.9857275929. The cubic root of 28729447 is about 306.2732653712.

The spelling of 28729447 in words is "twenty-eight million, seven hundred twenty-nine thousand, four hundred forty-seven".