21344001321 has 16 divisors (see below), whose sum is σ = 29109480128. Its totient is φ = 13906900800.

The previous prime is 21344001299. The next prime is 21344001377. The reversal of 21344001321 is 12310044312.

It is not a de Polignac number, because 21344001321 - 2⁶ = 21344001257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21344001521) 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, 342715 + ... + 400176.

It is an arithmetic number, because the mean of its divisors is an integer number (1819342508).

Almost surely, 2^21344001321 is an apocalyptic number.

It is an amenable number.

21344001321 is a deficient number, since it is larger than the sum of its proper divisors (7765478807).

21344001321 is a wasteful number, since it uses less digits than its factorization.

21344001321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743112.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21344001321 its reverse (12310044312), we get a palindrome (33654045633).

The spelling of 21344001321 in words is "twenty-one billion, three hundred forty-four million, one thousand, three hundred twenty-one".