21112121221012 has 24 divisors (see below), whose sum is σ = 37596613219200. Its totient is φ = 10370462150016.

The previous prime is 21112121221007. The next prime is 21112121221033. The reversal of 21112121221012 is 21012212121112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28435212 + ... + 29168227.

It is an arithmetic number, because the mean of its divisors is an integer number (1566525550800).

Almost surely, 2^{21112121221012} is an apocalyptic number.

It is an amenable number.

21112121221012 is a deficient number, since it is larger than the sum of its proper divisors (16484491998188).

21112121221012 is a wasteful number, since it uses less digits than its factorization.

21112121221012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57605055 (or 57605053 counting only the distinct ones).

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

Adding to 21112121221012 its reverse (21012212121112), we get a palindrome (42124333342124).

The spelling of 21112121221012 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, two hundred twenty-one thousand, twelve".