21000221311 has 4 divisors (see below), whose sum is σ = 21000609000. Its totient is φ = 20999833624.

The previous prime is 21000221309. The next prime is 21000221339. The reversal of 21000221311 is 11312200012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21000221311 - 2¹ = 21000221309 is a prime.

It is a super-2 number, since 2×21000221311² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000221291 and 21000221300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000221611) 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, 96196 + ... + 226393.

It is an arithmetic number, because the mean of its divisors is an integer number (5250152250).

Almost surely, 2^21000221311 is an apocalyptic number.

21000221311 is a deficient number, since it is larger than the sum of its proper divisors (387689).

21000221311 is an equidigital number, since it uses as much as digits as its factorization.

21000221311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387688.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21000221311 its reverse (11312200012), we get a palindrome (32312421323).

The spelling of 21000221311 in words is "twenty-one billion, two hundred twenty-one thousand, three hundred eleven".