20555219 has 2 divisors, whose sum is σ = 20555220. Its totient is φ = 20555218.

The previous prime is 20555209. The next prime is 20555221. The reversal of 20555219 is 91255502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20555219 - 2⁴ = 20555203 is a prime.

It is a super-2 number, since 2×20555219² = 845034056275922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 20555221, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20555191 and 20555200.

It is not a weakly prime, because it can be changed into another prime (20555209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10277609 + 10277610.

It is an arithmetic number, because the mean of its divisors is an integer number (10277610).

Almost surely, 2^20555219 is an apocalyptic number.

20555219 is a deficient number, since it is larger than the sum of its proper divisors (1).

20555219 is an equidigital number, since it uses as much as digits as its factorization.

20555219 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 20555219 is about 4533.7863866750. The cubic root of 20555219 is about 273.9306971263.

The spelling of 20555219 in words is "twenty million, five hundred fifty-five thousand, two hundred nineteen".