20646020042 has 8 divisors (see below), whose sum is σ = 30977786532. Its totient is φ = 10320091200.

The previous prime is 20646020011. The next prime is 20646020047. The reversal of 20646020042 is 24002064602.

20646020042 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 19296265921 + 1349754121 = 138911^2 + 36739^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 20646019993 and 20646020020.

It is not an unprimeable number, because it can be changed into a prime (20646020047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1450559 + ... + 1464722.

Almost surely, 2^20646020042 is an apocalyptic number.

20646020042 is a deficient number, since it is larger than the sum of its proper divisors (10331766490).

20646020042 is a wasteful number, since it uses less digits than its factorization.

20646020042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2918824.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 20646020042 its reverse (24002064602), we get a palindrome (44648084644).

The spelling of 20646020042 in words is "twenty billion, six hundred forty-six million, twenty thousand, forty-two".