21212021212 has 24 divisors (see below), whose sum is σ = 37499428512. Its totient is φ = 10497960000.

The previous prime is 21212021161. The next prime is 21212021221.

It is a happy number.

21212021212 is nontrivially palindromic in base 10.

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 7 ways as a sum of consecutive naturals, for example, 2137462 + ... + 2147362.

It is an arithmetic number, because the mean of its divisors is an integer number (1562476188).

Almost surely, 2^21212021212 is an apocalyptic number.

It is an amenable number.

21212021212 is a deficient number, since it is larger than the sum of its proper divisors (16287407300).

21212021212 is a wasteful number, since it uses less digits than its factorization.

21212021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15309 (or 15307 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

It can be divided in two parts, 212120 and 21212, that added together give a palindrome (233332).

The spelling of 21212021212 in words is "twenty-one billion, two hundred twelve million, twenty-one thousand, two hundred twelve".