21121021122120 has 64 divisors (see below), whose sum is σ = 70403403744000. Its totient is φ = 5632272298944.

The previous prime is 21121021122119. The next prime is 21121021122121. The reversal of 21121021122120 is 2122112012112.

21121021122120 is a `hidden beast` number, since 2 + 1 + 1 + 210 + 211 + 221 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (21121021122119) and next prime (21121021122121).

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

It is a junction number, because it is equal to n+sod(n) for n = 21121021122093 and 21121021122102.

It is not an unprimeable number, because it can be changed into a prime (21121021122121) 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 15 ways as a sum of consecutive naturals, for example, 9778249440 + ... + 9778251599.

It is an arithmetic number, because the mean of its divisors is an integer number (1100053183500).

Almost surely, 2^{21121021122120} is an apocalyptic number.

21121021122120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121021122120 is an abundant number, since it is smaller than the sum of its proper divisors (49282382621880).

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

21121021122120 is a wasteful number, since it uses less digits than its factorization.

21121021122120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19556501059 (or 19556501049 counting only the distinct ones).

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

Adding to 21121021122120 its reverse (2122112012112), we get a palindrome (23243133134232).

The spelling of 21121021122120 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one million, one hundred twenty-two thousand, one hundred twenty".