21211000120 has 32 divisors (see below), whose sum is σ = 48188106720. Its totient is φ = 8402025600.

The previous prime is 21211000117. The next prime is 21211000127. The reversal of 21211000120 is 2100011212.

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 = 21211000097 and 21211000106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211000127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2570031 + ... + 2578270.

It is an arithmetic number, because the mean of its divisors is an integer number (1505878335).

Almost surely, 2^21211000120 is an apocalyptic number.

21211000120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211000120 is an abundant number, since it is smaller than the sum of its proper divisors (26977106600).

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

21211000120 is a wasteful number, since it uses less digits than its factorization.

21211000120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5148415 (or 5148411 counting only the distinct ones).

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

Adding to 21211000120 its reverse (2100011212), we get a palindrome (23311011332).

The spelling of 21211000120 in words is "twenty-one billion, two hundred eleven million, one hundred twenty", and thus it is an aban number.