21322303521 has 4 divisors (see below), whose sum is σ = 28429738032. Its totient is φ = 14214869012.

The previous prime is 21322303517. The next prime is 21322303523. The reversal of 21322303521 is 12530322312.

It is a happy number.

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 21322303521 - 2² = 21322303517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21322303491 and 21322303500.

It is not an unprimeable number, because it can be changed into a prime (21322303523) 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, 3553717251 + ... + 3553717256.

It is an arithmetic number, because the mean of its divisors is an integer number (7107434508).

Almost surely, 2^21322303521 is an apocalyptic number.

It is an amenable number.

21322303521 is a deficient number, since it is larger than the sum of its proper divisors (7107434511).

21322303521 is an equidigital number, since it uses as much as digits as its factorization.

21322303521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7107434510.

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21322303521 its reverse (12530322312), we get a palindrome (33852625833).

The spelling of 21322303521 in words is "twenty-one billion, three hundred twenty-two million, three hundred three thousand, five hundred twenty-one".