20775779 has 2 divisors, whose sum is σ = 20775780. Its totient is φ = 20775778.

The previous prime is 20775767. The next prime is 20775793. The reversal of 20775779 is 97757702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20775779 - 2⁴ = 20775763 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20775709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10387889 + 10387890.

It is an arithmetic number, because the mean of its divisors is an integer number (10387890).

Almost surely, 2^20775779 is an apocalyptic number.

20775779 is a deficient number, since it is larger than the sum of its proper divisors (1).

20775779 is an equidigital number, since it uses as much as digits as its factorization.

20775779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216090, while the sum is 44.

The square root of 20775779 is about 4558.0455241254. The cubic root of 20775779 is about 274.9069834175.

The spelling of 20775779 in words is "twenty million, seven hundred seventy-five thousand, seven hundred seventy-nine".