28644947 has 2 divisors, whose sum is σ = 28644948. Its totient is φ = 28644946.

The previous prime is 28644943. The next prime is 28644991. The reversal of 28644947 is 74944682.

It is an a-pointer prime, because the next prime (28644991) can be obtained adding 28644947 to its sum of digits (44).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28644947 - 2² = 28644943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28644898 and 28644907.

It is not a weakly prime, because it can be changed into another prime (28644943) 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, 14322473 + 14322474.

It is an arithmetic number, because the mean of its divisors is an integer number (14322474).

Almost surely, 2^28644947 is an apocalyptic number.

28644947 is a deficient number, since it is larger than the sum of its proper divisors (1).

28644947 is an equidigital number, since it uses as much as digits as its factorization.

28644947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 44.

The square root of 28644947 is about 5352.0974393223. The cubic root of 28644947 is about 305.9726968106.

The spelling of 28644947 in words is "twenty-eight million, six hundred forty-four thousand, nine hundred forty-seven".