20646426443 has 4 divisors (see below), whose sum is σ = 21085712160. Its totient is φ = 20207140728.

The previous prime is 20646426439. The next prime is 20646426481. The reversal of 20646426443 is 34462464602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34462464602 = 2 ⋅17231232301.

It is a cyclic number.

It is not a de Polignac number, because 20646426443 - 2² = 20646426439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20646426443.

It is not an unprimeable number, because it can be changed into a prime (20646426413) 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, 219642788 + ... + 219642881.

It is an arithmetic number, because the mean of its divisors is an integer number (5271428040).

Almost surely, 2^20646426443 is an apocalyptic number.

20646426443 is a deficient number, since it is larger than the sum of its proper divisors (439285717).

20646426443 is an equidigital number, since it uses as much as digits as its factorization.

20646426443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439285716.

The product of its (nonzero) digits is 663552, while the sum is 41.

The spelling of 20646426443 in words is "twenty billion, six hundred forty-six million, four hundred twenty-six thousand, four hundred forty-three".