28640779 has 2 divisors, whose sum is σ = 28640780. Its totient is φ = 28640778.

The previous prime is 28640753. The next prime is 28640791. The reversal of 28640779 is 97704682.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28640779 - 2¹³ = 28632587 is a prime.

It is not a weakly prime, because it can be changed into another prime (28647779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14320389 + 14320390.

It is an arithmetic number, because the mean of its divisors is an integer number (14320390).

Almost surely, 2^28640779 is an apocalyptic number.

28640779 is a deficient number, since it is larger than the sum of its proper divisors (1).

28640779 is an equidigital number, since it uses as much as digits as its factorization.

28640779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 28640779 is about 5351.7080451011. The cubic root of 28640779 is about 305.9578558446.

The spelling of 28640779 in words is "twenty-eight million, six hundred forty thousand, seven hundred seventy-nine".