21404404433 has 4 divisors (see below), whose sum is σ = 21413511168. Its totient is φ = 21395297700.

The previous prime is 21404404397. The next prime is 21404404451. The reversal of 21404404433 is 33440440412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21404404433 - 2³⁰ = 20330662609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21404404396 and 21404404405.

It is not an unprimeable number, because it can be changed into a prime (21404404493) 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, 4549841 + ... + 4554542.

It is an arithmetic number, because the mean of its divisors is an integer number (5353377792).

Almost surely, 2^21404404433 is an apocalyptic number.

It is an amenable number.

21404404433 is a deficient number, since it is larger than the sum of its proper divisors (9106735).

21404404433 is an equidigital number, since it uses as much as digits as its factorization.

21404404433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9106734.

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 21404404433 its reverse (33440440412), we get a palindrome (54844844845).

The spelling of 21404404433 in words is "twenty-one billion, four hundred four million, four hundred four thousand, four hundred thirty-three".