21002120011220 has 24 divisors (see below), whose sum is σ = 45042844621824. Its totient is φ = 8222106557216.

The previous prime is 21002120011153. The next prime is 21002120011241. The reversal of 21002120011220 is 2211002120012.

It is a junction number, because it is equal to n+sod(n) for n = 21002120011195 and 21002120011204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11171339492 + ... + 11171341371.

It is an arithmetic number, because the mean of its divisors is an integer number (1876785192576).

Almost surely, 2^{21002120011220} is an apocalyptic number.

21002120011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002120011220 is an abundant number, since it is smaller than the sum of its proper divisors (24040724610604).

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

21002120011220 is a wasteful number, since it uses less digits than its factorization.

21002120011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22342680919 (or 22342680917 counting only the distinct ones).

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

Adding to 21002120011220 its reverse (2211002120012), we get a palindrome (23213122131232).

The spelling of 21002120011220 in words is "twenty-one trillion, two billion, one hundred twenty million, eleven thousand, two hundred twenty".