21212021100412 has 12 divisors (see below), whose sum is σ = 37252206669496. Its totient is φ = 10568533480560.

The previous prime is 21212021100383. The next prime is 21212021100443. The reversal of 21212021100412 is 21400112021212.

It is a self number, because there is not a number n which added to its sum of digits gives 21212021100412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9369266139 + ... + 9369268402.

Almost surely, 2^{21212021100412} is an apocalyptic number.

It is an amenable number.

21212021100412 is a deficient number, since it is larger than the sum of its proper divisors (16040185569084).

21212021100412 is a wasteful number, since it uses less digits than its factorization.

21212021100412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18738534828 (or 18738534826 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21212021100412 its reverse (21400112021212), we get a palindrome (42612133121624).

The spelling of 21212021100412 in words is "twenty-one trillion, two hundred twelve billion, twenty-one million, one hundred thousand, four hundred twelve".