21120212120 has 64 divisors (see below), whose sum is σ = 54816756480. Its totient is φ = 7173530496.

The previous prime is 21120212027. The next prime is 21120212129. The reversal of 21120212120 is 2121202112.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21120212095 and 21120212104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120212129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 322514 + ... + 382433.

It is an arithmetic number, because the mean of its divisors is an integer number (856511820).

Almost surely, 2^21120212120 is an apocalyptic number.

21120212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120212120 is an abundant number, since it is smaller than the sum of its proper divisors (33696544360).

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

21120212120 is a wasteful number, since it uses less digits than its factorization.

21120212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705072 (or 705068 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21120212120 its reverse (2121202112), we get a palindrome (23241414232).

It can be divided in two parts, 211202 and 12120, that added together give a palindrome (223322).

The spelling of 21120212120 in words is "twenty-one billion, one hundred twenty million, two hundred twelve thousand, one hundred twenty".