21210212020220 has 24 divisors (see below), whose sum is σ = 45206242935504. Its totient is φ = 8357456676096.

The previous prime is 21210212020213. The next prime is 21210212020229. The reversal of 21210212020220 is 2202021201212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210212020229) 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, 7914256877 + ... + 7914259556.

It is an arithmetic number, because the mean of its divisors is an integer number (1883593455646).

Almost surely, 2^{21210212020220} is an apocalyptic number.

21210212020220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210212020220 is an abundant number, since it is smaller than the sum of its proper divisors (23996030915284).

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

21210212020220 is a wasteful number, since it uses less digits than its factorization.

21210212020220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15828516509 (or 15828516507 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21210212020220 its reverse (2202021201212), we get a palindrome (23412233221432).

The spelling of 21210212020220 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, twenty thousand, two hundred twenty".