21444330401 has 16 divisors (see below), whose sum is σ = 24031669200. Its totient is φ = 19112131584.

The previous prime is 21444330359. The next prime is 21444330431. The reversal of 21444330401 is 10403344412.

It can be written as a sum of positive squares in 8 ways, for example, as 15519179776 + 5925150625 = 124576^2 + 76975^2 .

It is not a de Polignac number, because 21444330401 - 2¹⁸ = 21444068257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21444330431) 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, 104576 + ... + 232001.

It is an arithmetic number, because the mean of its divisors is an integer number (1501979325).

Almost surely, 2^21444330401 is an apocalyptic number.

It is an amenable number.

21444330401 is a deficient number, since it is larger than the sum of its proper divisors (2587338799).

21444330401 is an equidigital number, since it uses as much as digits as its factorization.

21444330401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336645 (or 336619 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21444330401 its reverse (10403344412), we get a palindrome (31847674813).

The spelling of 21444330401 in words is "twenty-one billion, four hundred forty-four million, three hundred thirty thousand, four hundred one".