21212011100 has 36 divisors (see below), whose sum is σ = 52605789264. Its totient is φ = 7272689280.

The previous prime is 21212011063. The next prime is 21212011109. The reversal of 21212011100 is 111021212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212011109) 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 11 ways as a sum of consecutive naturals, for example, 15150737 + ... + 15152136.

It is an arithmetic number, because the mean of its divisors is an integer number (1461271924).

Almost surely, 2^21212011100 is an apocalyptic number.

21212011100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212011100 is an abundant number, since it is smaller than the sum of its proper divisors (31393778164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21212011100 is a wasteful number, since it uses less digits than its factorization.

21212011100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30302894 (or 30302887 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21212011100 its reverse (111021212), we get a palindrome (21323032312).

The spelling of 21212011100 in words is "twenty-one billion, two hundred twelve million, eleven thousand, one hundred".