21420020033 has 16 divisors (see below), whose sum is σ = 22628833920. Its totient is φ = 20253878400.

The previous prime is 21420019981. The next prime is 21420020051. The reversal of 21420020033 is 33002002412.

It is a cyclic number.

It is not a de Polignac number, because 21420020033 - 2⁶ = 21420019969 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21420019993 and 21420020020.

It is not an unprimeable number, because it can be changed into a prime (21420020333) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109391 + ... + 234107.

It is an arithmetic number, because the mean of its divisors is an integer number (1414302120).

Almost surely, 2^21420020033 is an apocalyptic number.

It is an amenable number.

21420020033 is a deficient number, since it is larger than the sum of its proper divisors (1208813887).

21420020033 is a wasteful number, since it uses less digits than its factorization.

21420020033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124888.

The product of its (nonzero) digits is 288, while the sum is 17.

Adding to 21420020033 its reverse (33002002412), we get a palindrome (54422022445).

The spelling of 21420020033 in words is "twenty-one billion, four hundred twenty million, twenty thousand, thirty-three".