21212110100100 has 36 divisors (see below), whose sum is σ = 61373705223824. Its totient is φ = 5656562693280.

The previous prime is 21212110100017. The next prime is 21212110100119. The reversal of 21212110100100 is 100101121212.

It is a super-3 number, since 3×21212110100100³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35353516534 + ... + 35353517133.

Almost surely, 2^{21212110100100} is an apocalyptic number.

21212110100100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212110100100 is an abundant number, since it is smaller than the sum of its proper divisors (40161595123724).

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

21212110100100 is a wasteful number, since it uses less digits than its factorization.

21212110100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70707033684 (or 70707033677 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21212110100100 its reverse (100101121212), we get a palindrome (21312211221312).

The spelling of 21212110100100 in words is "twenty-one trillion, two hundred twelve billion, one hundred ten million, one hundred thousand, one hundred".