21121212121102 has 32 divisors (see below), whose sum is σ = 32154530591232. Its totient is φ = 10403764001664.

The previous prime is 21121212121069. The next prime is 21121212121223. The reversal of 21121212121102 is 20112121212112.

It is a happy number.

It is a super-2 number, since 2×21121212121102² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121212121102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 819814473 + ... + 819840235.

It is an arithmetic number, because the mean of its divisors is an integer number (1004829080976).

Almost surely, 2^{21121212121102} is an apocalyptic number.

21121212121102 is a deficient number, since it is larger than the sum of its proper divisors (11033318470130).

21121212121102 is a wasteful number, since it uses less digits than its factorization.

21121212121102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39672.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21121212121102 its reverse (20112121212112), we get a palindrome (41233333333214).

It can be divided in two parts, 2112121212110 and 2, that added together give a palindrome (2112121212112).

The spelling of 21121212121102 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, one hundred two".