20355109 has 2 divisors, whose sum is σ = 20355110. Its totient is φ = 20355108.

The previous prime is 20355107. The next prime is 20355121. The reversal of 20355109 is 90155302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19554084 + 801025 = 4422^2 + 895^2 .

It is a cyclic number.

It is not a de Polignac number, because 20355109 - 2¹ = 20355107 is a prime.

Together with 20355107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20355107) 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, 10177554 + 10177555.

It is an arithmetic number, because the mean of its divisors is an integer number (10177555).

Almost surely, 2^20355109 is an apocalyptic number.

It is an amenable number.

20355109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20355109 is an equidigital number, since it uses as much as digits as its factorization.

20355109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 20355109 is about 4511.6636621096. The cubic root of 20355109 is about 273.0388697131.

The spelling of 20355109 in words is "twenty million, three hundred fifty-five thousand, one hundred nine".