21214340321 has 4 divisors (see below), whose sum is σ = 21665709312. Its totient is φ = 20762971332.

The previous prime is 21214340269. The next prime is 21214340363. The reversal of 21214340321 is 12304341212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21214340321 - 2¹⁸ = 21214078177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21214340621) 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, 225684425 + ... + 225684518.

It is an arithmetic number, because the mean of its divisors is an integer number (5416427328).

Almost surely, 2^21214340321 is an apocalyptic number.

It is an amenable number.

21214340321 is a deficient number, since it is larger than the sum of its proper divisors (451368991).

21214340321 is an equidigital number, since it uses as much as digits as its factorization.

21214340321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451368990.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21214340321 its reverse (12304341212), we get a palindrome (33518681533).

The spelling of 21214340321 in words is "twenty-one billion, two hundred fourteen million, three hundred forty thousand, three hundred twenty-one".