21111003221 has 12 divisors (see below), whose sum is σ = 26519608416. Its totient is φ = 16450131720.

The previous prime is 21111003211. The next prime is 21111003239. The reversal of 21111003221 is 12230011112.

It is not a de Polignac number, because 21111003221 - 2¹⁸ = 21110741077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111003196 and 21111003205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111003211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12461375 + ... + 12463068.

It is an arithmetic number, because the mean of its divisors is an integer number (2209967368).

Almost surely, 2^21111003221 is an apocalyptic number.

It is an amenable number.

21111003221 is a deficient number, since it is larger than the sum of its proper divisors (5408605195).

21111003221 is a wasteful number, since it uses less digits than its factorization.

21111003221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24924472 (or 24924461 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21111003221 its reverse (12230011112), we get a palindrome (33341014333).

The spelling of 21111003221 in words is "twenty-one billion, one hundred eleven million, three thousand, two hundred twenty-one".