21000121122112 has 56 divisors (see below), whose sum is σ = 45491650362720. Its totient is φ = 9538966632960.

The previous prime is 21000121122091. The next prime is 21000121122121. The reversal of 21000121122112 is 21122112100012.

It is a Harshad number since it is a multiple of its sum of digits (16).

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, 9195523 + ... + 11249794.

Almost surely, 2^{21000121122112} is an apocalyptic number.

21000121122112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21000121122112 is an abundant number, since it is smaller than the sum of its proper divisors (24491529240608).

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

21000121122112 is a wasteful number, since it uses less digits than its factorization.

21000121122112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20446799 (or 20446789 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21000121122112 its reverse (21122112100012), we get a palindrome (42122233222124).

The spelling of 21000121122112 in words is "twenty-one trillion, one hundred twenty-one million, one hundred twenty-two thousand, one hundred twelve".