21203211111 has 8 divisors (see below), whose sum is σ = 28804362480. Its totient is φ = 13868766912.

The previous prime is 21203211109. The next prime is 21203211149. The reversal of 21203211111 is 11111230212.

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

It is not a de Polignac number, because 21203211111 - 2¹ = 21203211109 is a prime.

It is a super-3 number, since 3×21203211111³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203211511) 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 7 ways as a sum of consecutive naturals, for example, 66676606 + ... + 66676923.

It is an arithmetic number, because the mean of its divisors is an integer number (3600545310).

Almost surely, 2^21203211111 is an apocalyptic number.

21203211111 is a deficient number, since it is larger than the sum of its proper divisors (7601151369).

21203211111 is a wasteful number, since it uses less digits than its factorization.

21203211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133353585.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21203211111 its reverse (11111230212), we get a palindrome (32314441323).

The spelling of 21203211111 in words is "twenty-one billion, two hundred three million, two hundred eleven thousand, one hundred eleven".