21121000000012 has 96 divisors (see below), whose sum is σ = 43927019136000. Its totient is φ = 8777678192640.

The previous prime is 21120999999919. The next prime is 21121000000013. The reversal of 21121000000012 is 21000000012112.

It is not an unprimeable number, because it can be changed into a prime (21121000000013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55255564 + ... + 55636492.

It is an arithmetic number, because the mean of its divisors is an integer number (457573116000).

Almost surely, 2^{21121000000012} is an apocalyptic number.

21121000000012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21121000000012 is an abundant number, since it is smaller than the sum of its proper divisors (22806019135988).

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

21121000000012 is a wasteful number, since it uses less digits than its factorization.

21121000000012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383279 (or 383277 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21121000000012 its reverse (21000000012112), we get a palindrome (42121000012124).

The spelling of 21121000000012 in words is "twenty-one trillion, one hundred twenty-one billion, twelve", and thus it is an aban number.