21112211021 has 8 divisors (see below), whose sum is σ = 23172802464. Its totient is φ = 19075169520.

The previous prime is 21112211011. The next prime is 21112211023. The reversal of 21112211021 is 12011221112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21112211021 - 2¹⁰ = 21112209997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112210987 and 21112211005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112211023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5885606 + ... + 5889191.

It is an arithmetic number, because the mean of its divisors is an integer number (2896600308).

Almost surely, 2^21112211021 is an apocalyptic number.

It is an amenable number.

21112211021 is a deficient number, since it is larger than the sum of its proper divisors (2060591443).

21112211021 is a wasteful number, since it uses less digits than its factorization.

21112211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11774971.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21112211021 its reverse (12011221112), we get a palindrome (33123432133).

The spelling of 21112211021 in words is "twenty-one billion, one hundred twelve million, two hundred eleven thousand, twenty-one".