20420443 has 2 divisors, whose sum is σ = 20420444. Its totient is φ = 20420442.

The previous prime is 20420377. The next prime is 20420453. The reversal of 20420443 is 34402402.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20420443 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20420443.

It is not a weakly prime, because it can be changed into another prime (20420453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210221 + 10210222.

It is an arithmetic number, because the mean of its divisors is an integer number (10210222).

Almost surely, 2^20420443 is an apocalyptic number.

20420443 is a deficient number, since it is larger than the sum of its proper divisors (1).

20420443 is an equidigital number, since it uses as much as digits as its factorization.

20420443 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 19.

The square root of 20420443 is about 4518.8984277144. The cubic root of 20420443 is about 273.3306829342.

Adding to 20420443 its reverse (34402402), we get a palindrome (54822845).

The spelling of 20420443 in words is "twenty million, four hundred twenty thousand, four hundred forty-three".