21120121202112 has 672 divisors, whose sum is σ = 64252503244800. Its totient is φ = 6626543616000.

The previous prime is 21120121202111. The next prime is 21120121202149. The reversal of 21120121202112 is 21120212102112.

21120121202112 is a `hidden beast` number, since 211 + 20 + 121 + 202 + 112 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120121202111) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 14357661537 + ... + 14357663007.

Almost surely, 2^{21120121202112} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21120121202112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32126251622400).

21120121202112 is an abundant number, since it is smaller than the sum of its proper divisors (43132382042688).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21120121202112 is a wasteful number, since it uses less digits than its factorization.

21120121202112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1785 (or 1772 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21120121202112 its reverse (21120212102112), we get a palindrome (42240333304224).

The spelling of 21120121202112 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty-one million, two hundred two thousand, one hundred twelve".