21210002121220 has 48 divisors (see below), whose sum is σ = 48614740574400. Its totient is φ = 7708830600320.

The previous prime is 21210002121179. The next prime is 21210002121271. The reversal of 21210002121220 is 2212120001212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21210002121194 and 21210002121203.

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, 23922655 + ... + 24793414.

It is an arithmetic number, because the mean of its divisors is an integer number (1012807095300).

Almost surely, 2^{21210002121220} is an apocalyptic number.

21210002121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210002121220 is an abundant number, since it is smaller than the sum of its proper divisors (27404738453180).

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

21210002121220 is a wasteful number, since it uses less digits than its factorization.

21210002121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48718068 (or 48718066 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21210002121220 its reverse (2212120001212), we get a palindrome (23422122122432).

The spelling of 21210002121220 in words is "twenty-one trillion, two hundred ten billion, two million, one hundred twenty-one thousand, two hundred twenty".