21000050321 has 4 divisors (see below), whose sum is σ = 21037351152. Its totient is φ = 20962749492.

The previous prime is 21000050317. The next prime is 21000050339. The reversal of 21000050321 is 12305000012.

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 21000050321 - 2² = 21000050317 is a prime.

It is a super-2 number, since 2×21000050321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21000050296 and 21000050305.

It is not an unprimeable number, because it can be changed into a prime (21000050021) 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, 18649571 + ... + 18650696.

It is an arithmetic number, because the mean of its divisors is an integer number (5259337788).

Almost surely, 2^21000050321 is an apocalyptic number.

It is an amenable number.

21000050321 is a deficient number, since it is larger than the sum of its proper divisors (37300831).

21000050321 is an equidigital number, since it uses as much as digits as its factorization.

21000050321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37300830.

The product of its (nonzero) digits is 60, while the sum is 14.

Adding to 21000050321 its reverse (12305000012), we get a palindrome (33305050333).

The spelling of 21000050321 in words is "twenty-one billion, fifty thousand, three hundred twenty-one".