20420123443 has 4 divisors (see below), whose sum is σ = 20485363768. Its totient is φ = 20354883120.

The previous prime is 20420123411. The next prime is 20420123447. The reversal of 20420123443 is 34432102402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34432102402 = 2 ⋅17216051201.

It is a cyclic number.

It is not a de Polignac number, because 20420123443 - 2⁵ = 20420123411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20420123447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32619693 + ... + 32620318.

It is an arithmetic number, because the mean of its divisors is an integer number (5121340942).

Almost surely, 2^20420123443 is an apocalyptic number.

20420123443 is a deficient number, since it is larger than the sum of its proper divisors (65240325).

20420123443 is an equidigital number, since it uses as much as digits as its factorization.

20420123443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65240324.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 20420123443 its reverse (34432102402), we get a palindrome (54852225845).

The spelling of 20420123443 in words is "twenty billion, four hundred twenty million, one hundred twenty-three thousand, four hundred forty-three".