20081779 has 2 divisors, whose sum is σ = 20081780. Its totient is φ = 20081778.

The previous prime is 20081741. The next prime is 20081797. The reversal of 20081779 is 97718002.

Together with next prime (20081797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20081779 - 2¹⁹ = 19557491 is a prime.

It is equal to p_1275496 and since 20081779 and 1275496 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20087779) 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, 10040889 + 10040890.

It is an arithmetic number, because the mean of its divisors is an integer number (10040890).

Almost surely, 2^20081779 is an apocalyptic number.

20081779 is a deficient number, since it is larger than the sum of its proper divisors (1).

20081779 is an equidigital number, since it uses as much as digits as its factorization.

20081779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 20081779 is about 4481.2697977247. The cubic root of 20081779 is about 271.8112291352.

The spelling of 20081779 in words is "twenty million, eighty-one thousand, seven hundred seventy-nine".