21212203311 has 24 divisors (see below), whose sum is σ = 33042784320. Its totient is φ = 13035456576.

The previous prime is 21212203297. The next prime is 21212203349. The reversal of 21212203311 is 11330221212.

21212203311 is a `hidden beast` number, since 212 + 122 + 0 + 331 + 1 = 666.

It is not a de Polignac number, because 21212203311 - 2⁶ = 21212203247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212203351) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41956 + ... + 210201.

It is an arithmetic number, because the mean of its divisors is an integer number (1376782680).

Almost surely, 2^21212203311 is an apocalyptic number.

21212203311 is a deficient number, since it is larger than the sum of its proper divisors (11830581009).

21212203311 is a wasteful number, since it uses less digits than its factorization.

21212203311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252895 (or 252892 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21212203311 its reverse (11330221212), we get a palindrome (32542424523).

The spelling of 21212203311 in words is "twenty-one billion, two hundred twelve million, two hundred three thousand, three hundred eleven".