21210121201220 has 48 divisors (see below), whose sum is σ = 50906940497280. Its totient is φ = 7271663038464.

The previous prime is 21210121201201. The next prime is 21210121201223. The reversal of 21210121201220 is 2210212101212.

It is not an unprimeable number, because it can be changed into a prime (21210121201223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1236989 + ... + 6629508.

It is an arithmetic number, because the mean of its divisors is an integer number (1060561260360).

Almost surely, 2^{21210121201220} is an apocalyptic number.

21210121201220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210121201220 is an abundant number, since it is smaller than the sum of its proper divisors (29696819296060).

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

21210121201220 is a wasteful number, since it uses less digits than its factorization.

21210121201220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7885772 (or 7885770 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21210121201220 its reverse (2210212101212), we get a palindrome (23420333302432).

The spelling of 21210121201220 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty-one million, two hundred one thousand, two hundred twenty".