20455559 has 2 divisors, whose sum is σ = 20455560. Its totient is φ = 20455558.

The previous prime is 20455553. The next prime is 20455601. The reversal of 20455559 is 95555402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20455559 - 2⁴ = 20455543 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20455553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10227779 + 10227780.

It is an arithmetic number, because the mean of its divisors is an integer number (10227780).

Almost surely, 2^20455559 is an apocalyptic number.

20455559 is a deficient number, since it is larger than the sum of its proper divisors (1).

20455559 is an equidigital number, since it uses as much as digits as its factorization.

20455559 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45000, while the sum is 35.

The square root of 20455559 is about 4522.7822189444. The cubic root of 20455559 is about 273.4872708466.

The spelling of 20455559 in words is "twenty million, four hundred fifty-five thousand, five hundred fifty-nine".