21113411221 has 4 divisors (see below), whose sum is σ = 24129612832. Its totient is φ = 18097209612.

The previous prime is 21113411117. The next prime is 21113411233. The reversal of 21113411221 is 12211431112.

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 21113411221 - 2¹¹ = 21113409173 is a prime.

It is a super-2 number, since 2×21113411221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113411251) 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, 1508100795 + ... + 1508100808.

It is an arithmetic number, because the mean of its divisors is an integer number (6032403208).

Almost surely, 2^21113411221 is an apocalyptic number.

It is an amenable number.

21113411221 is a deficient number, since it is larger than the sum of its proper divisors (3016201611).

21113411221 is an equidigital number, since it uses as much as digits as its factorization.

21113411221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3016201610.

The product of its digits is 96, while the sum is 19.

Adding to 21113411221 its reverse (12211431112), we get a palindrome (33324842333).

The spelling of 21113411221 in words is "twenty-one billion, one hundred thirteen million, four hundred eleven thousand, two hundred twenty-one".