21121212102 has 16 divisors (see below), whose sum is σ = 42260512320. Its totient is φ = 7037389352.

The previous prime is 21121212089. The next prime is 21121212103. The reversal of 21121212102 is 20121212112.

It is a super-2 number, since 2×21121212102² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121212103) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 738468 + ... + 766535.

It is an arithmetic number, because the mean of its divisors is an integer number (2641282020).

Almost surely, 2^21121212102 is an apocalyptic number.

21121212102 is an abundant number, since it is smaller than the sum of its proper divisors (21139300218).

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

21121212102 is a wasteful number, since it uses less digits than its factorization.

21121212102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1507347.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21121212102 its reverse (20121212112), we get a palindrome (41242424214).

The spelling of 21121212102 in words is "twenty-one billion, one hundred twenty-one million, two hundred twelve thousand, one hundred two".