28920779 has 2 divisors, whose sum is σ = 28920780. Its totient is φ = 28920778.

The previous prime is 28920767. The next prime is 28920781. The reversal of 28920779 is 97702982.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28920779 - 2⁸ = 28920523 is a prime.

It is a super-2 number, since 2×28920779² = 1672822915933682, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 28920781, 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 (28920719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14460389 + 14460390.

It is an arithmetic number, because the mean of its divisors is an integer number (14460390).

Almost surely, 2^28920779 is an apocalyptic number.

28920779 is a deficient number, since it is larger than the sum of its proper divisors (1).

28920779 is an equidigital number, since it uses as much as digits as its factorization.

28920779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 28920779 is about 5377.8042917161. The cubic root of 28920779 is about 306.9516665023.

The spelling of 28920779 in words is "twenty-eight million, nine hundred twenty thousand, seven hundred seventy-nine".