20055643 has 2 divisors, whose sum is σ = 20055644. Its totient is φ = 20055642.

The previous prime is 20055619. The next prime is 20055647. The reversal of 20055643 is 34655002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20055643 - 2⁵ = 20055611 is a prime.

It is a super-2 number, since 2×20055643² = 804457632286898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20055647) 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, 10027821 + 10027822.

It is an arithmetic number, because the mean of its divisors is an integer number (10027822).

Almost surely, 2^20055643 is an apocalyptic number.

20055643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20055643 is an equidigital number, since it uses as much as digits as its factorization.

20055643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 20055643 is about 4478.3527105399. The cubic root of 20055643 is about 271.6932591347.

The spelling of 20055643 in words is "twenty million, fifty-five thousand, six hundred forty-three".