21212110102 has 4 divisors (see below), whose sum is σ = 31818165156. Its totient is φ = 10606055050.

The previous prime is 21212110097. The next prime is 21212110109. The reversal of 21212110102 is 20101121212.

It is a semiprime because it is the product of two primes.

It is a super-3 number, since 3×21212110102³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212110109) 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 as a sum of consecutive naturals, namely, 5303027524 + ... + 5303027527.

It is an arithmetic number, because the mean of its divisors is an integer number (7954541289).

Almost surely, 2^21212110102 is an apocalyptic number.

21212110102 is a deficient number, since it is larger than the sum of its proper divisors (10606055054).

21212110102 is a wasteful number, since it uses less digits than its factorization.

21212110102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10606055053.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21212110102 its reverse (20101121212), we get a palindrome (41313231314).

The spelling of 21212110102 in words is "twenty-one billion, two hundred twelve million, one hundred ten thousand, one hundred two".