21204122043 has 16 divisors (see below), whose sum is σ = 30483806976. Its totient is φ = 13032892320.

The previous prime is 21204122033. The next prime is 21204122053. The reversal of 21204122043 is 34022140212.

It is an interprime number because it is at equal distance from previous prime (21204122033) and next prime (21204122053).

It is not a de Polignac number, because 21204122043 - 2⁸ = 21204121787 is a prime.

It is a super-2 number, since 2×21204122043² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21204122003) 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, 296463 + ... + 360968.

It is an arithmetic number, because the mean of its divisors is an integer number (1905237936).

Almost surely, 2^21204122043 is an apocalyptic number.

21204122043 is a deficient number, since it is larger than the sum of its proper divisors (9279684933).

21204122043 is a wasteful number, since it uses less digits than its factorization.

21204122043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658274.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21204122043 its reverse (34022140212), we get a palindrome (55226262255).

The spelling of 21204122043 in words is "twenty-one billion, two hundred four million, one hundred twenty-two thousand, forty-three".