21201210120 has 64 divisors (see below), whose sum is σ = 63769835520. Its totient is φ = 5638882304.

The previous prime is 21201210091. The next prime is 21201210133. The reversal of 21201210120 is 2101210212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21201210096 and 21201210105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 184689 + ... + 276608.

It is an arithmetic number, because the mean of its divisors is an integer number (996403680).

Almost surely, 2^21201210120 is an apocalyptic number.

21201210120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201210120 is an abundant number, since it is smaller than the sum of its proper divisors (42568625400).

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

21201210120 is a wasteful number, since it uses less digits than its factorization.

21201210120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461694 (or 461690 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21201210120 its reverse (2101210212), we get a palindrome (23302420332).

The spelling of 21201210120 in words is "twenty-one billion, two hundred one million, two hundred ten thousand, one hundred twenty".