20779289 has 2 divisors, whose sum is σ = 20779290. Its totient is φ = 20779288.

The previous prime is 20779273. The next prime is 20779301. The reversal of 20779289 is 98297702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12369289 + 8410000 = 3517^2 + 2900^2 .

It is a cyclic number.

It is not a de Polignac number, because 20779289 - 2⁴ = 20779273 is a prime.

It is not a weakly prime, because it can be changed into another prime (20779259) 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, 10389644 + 10389645.

It is an arithmetic number, because the mean of its divisors is an integer number (10389645).

Almost surely, 2^20779289 is an apocalyptic number.

It is an amenable number.

20779289 is a deficient number, since it is larger than the sum of its proper divisors (1).

20779289 is an equidigital number, since it uses as much as digits as its factorization.

20779289 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 20779289 is about 4558.4305413157. The cubic root of 20779289 is about 274.9224640913.

The spelling of 20779289 in words is "twenty million, seven hundred seventy-nine thousand, two hundred eighty-nine".