21210100212 has 72 divisors (see below), whose sum is σ = 57596869344. Its totient is φ = 6057229248.

The previous prime is 21210100207. The next prime is 21210100229. The reversal of 21210100212 is 21200101212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1496463 + ... + 1510569.

Almost surely, 2^21210100212 is an apocalyptic number.

It is an amenable number.

21210100212 is an abundant number, since it is smaller than the sum of its proper divisors (36386769132).

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

21210100212 is a wasteful number, since it uses less digits than its factorization.

21210100212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16685 (or 16676 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21210100212 its reverse (21200101212), we get a palindrome (42410201424).

The spelling of 21210100212 in words is "twenty-one billion, two hundred ten million, one hundred thousand, two hundred twelve".