13444321421 has 4 divisors (see below), whose sum is σ = 13542455292. Its totient is φ = 13346187552.

The previous prime is 13444321409. The next prime is 13444321487. The reversal of 13444321421 is 12412344431.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12412344431 = 4973 ⋅2495947.

It can be written as a sum of positive squares in 2 ways, for example, as 3043177225 + 10401144196 = 55165^2 + 101986^2 .

It is a cyclic number.

It is not a de Polignac number, because 13444321421 - 2¹⁰ = 13444320397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13444321921) 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, 49066730 + ... + 49067003.

It is an arithmetic number, because the mean of its divisors is an integer number (3385613823).

Almost surely, 2^13444321421 is an apocalyptic number.

It is an amenable number.

13444321421 is a deficient number, since it is larger than the sum of its proper divisors (98133871).

13444321421 is an equidigital number, since it uses as much as digits as its factorization.

13444321421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98133870.

The product of its digits is 9216, while the sum is 29.

Adding to 13444321421 its reverse (12412344431), we get a palindrome (25856665852).

The spelling of 13444321421 in words is "thirteen billion, four hundred forty-four million, three hundred twenty-one thousand, four hundred twenty-one".