21411404430121 has 4 divisors (see below), whose sum is σ = 21411486546772. Its totient is φ = 21411322313472.

The previous prime is 21411404430107. The next prime is 21411404430127. The reversal of 21411404430121 is 12103440411412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4368246301225 + 17043158128896 = 2090035^2 + 4128336^2 .

It is a cyclic number.

It is not a de Polignac number, because 21411404430121 - 2¹⁵ = 21411404397353 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 21411404430121.

It is not an unprimeable number, because it can be changed into a prime (21411404430127) 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, 40665960 + ... + 41189113.

It is an arithmetic number, because the mean of its divisors is an integer number (5352871636693).

Almost surely, 2^{21411404430121} is an apocalyptic number.

It is an amenable number.

21411404430121 is a deficient number, since it is larger than the sum of its proper divisors (82116651).

21411404430121 is an equidigital number, since it uses as much as digits as its factorization.

21411404430121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82116650.

The product of its (nonzero) digits is 3072, while the sum is 28.

Adding to 21411404430121 its reverse (12103440411412), we get a palindrome (33514844841533).

The spelling of 21411404430121 in words is "twenty-one trillion, four hundred eleven billion, four hundred four million, four hundred thirty thousand, one hundred twenty-one".