21212102 has 8 divisors (see below), whose sum is σ = 32266512. Its totient is φ = 10456600.

The previous prime is 21212101. The next prime is 21212111. The reversal of 21212102 is 20121212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×21212102³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74549 + ... + 74832.

It is an arithmetic number, because the mean of its divisors is an integer number (4033314).

Almost surely, 2^21212102 is an apocalyptic number.

21212102 is a deficient number, since it is larger than the sum of its proper divisors (11054410).

21212102 is a wasteful number, since it uses less digits than its factorization.

21212102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149454.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21212102 is about 4605.6597790110. The cubic root of 21212102 is about 276.8181544860.

Adding to 21212102 its reverse (20121212), we get a palindrome (41333314).

It can be divided in two parts, 2121210 and 2, that added together give a palindrome (2121212).

The spelling of 21212102 in words is "twenty-one million, two hundred twelve thousand, one hundred two".