21320301021 has 4 divisors (see below), whose sum is σ = 28427068032. Its totient is φ = 14213534012.

The previous prime is 21320301019. The next prime is 21320301073. The reversal of 21320301021 is 12010302312.

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 21320301021 - 2¹ = 21320301019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320301011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3553383501 + ... + 3553383506.

It is an arithmetic number, because the mean of its divisors is an integer number (7106767008).

Almost surely, 2^21320301021 is an apocalyptic number.

It is an amenable number.

21320301021 is a deficient number, since it is larger than the sum of its proper divisors (7106767011).

21320301021 is an equidigital number, since it uses as much as digits as its factorization.

21320301021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7106767010.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21320301021 its reverse (12010302312), we get a palindrome (33330603333).

The spelling of 21320301021 in words is "twenty-one billion, three hundred twenty million, three hundred one thousand, twenty-one".