21210010120 has 128 divisors (see below), whose sum is σ = 52855649280. Its totient is φ = 7610112000.

The previous prime is 21210010097. The next prime is 21210010177. The reversal of 21210010120 is 2101001212.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21210010097 and 21210010106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5775885 + ... + 5779555.

It is an arithmetic number, because the mean of its divisors is an integer number (412934760).

Almost surely, 2^21210010120 is an apocalyptic number.

21210010120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21210010120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26427824640).

21210010120 is an abundant number, since it is smaller than the sum of its proper divisors (31645639160).

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

21210010120 is a wasteful number, since it uses less digits than its factorization.

21210010120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4007 (or 4003 counting only the distinct ones).

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

Adding to 21210010120 its reverse (2101001212), we get a palindrome (23311011332).

The spelling of 21210010120 in words is "twenty-one billion, two hundred ten million, ten thousand, one hundred twenty".