21344240401 has 24 divisors (see below), whose sum is σ = 25309913832. Its totient is φ = 17917785600.

The previous prime is 21344240399. The next prime is 21344240447. The reversal of 21344240401 is 10404244312.

It can be written as a sum of positive squares in 4 ways, for example, as 5937473025 + 15406767376 = 77055^2 + 124124^2 .

It is not a de Polignac number, because 21344240401 - 2¹ = 21344240399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21344244401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11131 + ... + 206911.

It is an arithmetic number, because the mean of its divisors is an integer number (1054579743).

Almost surely, 2^21344240401 is an apocalyptic number.

It is an amenable number.

21344240401 is a deficient number, since it is larger than the sum of its proper divisors (3965673431).

21344240401 is a wasteful number, since it uses less digits than its factorization.

21344240401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195873 (or 195862 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21344240401 its reverse (10404244312), we get a palindrome (31748484713).

The spelling of 21344240401 in words is "twenty-one billion, three hundred forty-four million, two hundred forty thousand, four hundred one".