20355779 has 2 divisors, whose sum is σ = 20355780. Its totient is φ = 20355778.

The previous prime is 20355773. The next prime is 20355781. The reversal of 20355779 is 97755302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20355779 - 2⁸ = 20355523 is a prime.

Together with 20355781, 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 (20355773) 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, 10177889 + 10177890.

It is an arithmetic number, because the mean of its divisors is an integer number (10177890).

Almost surely, 2^20355779 is an apocalyptic number.

20355779 is a deficient number, since it is larger than the sum of its proper divisors (1).

20355779 is an equidigital number, since it uses as much as digits as its factorization.

20355779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 66150, while the sum is 38.

The square root of 20355779 is about 4511.7379134874. The cubic root of 20355779 is about 273.0418654235.

The spelling of 20355779 in words is "twenty million, three hundred fifty-five thousand, seven hundred seventy-nine".