21210122210220 has 144 divisors (see below), whose sum is σ = 70644956342688. Its totient is φ = 5323324769280.

The previous prime is 21210122210171. The next prime is 21210122210281. The reversal of 21210122210220 is 2201222101212.

It is a happy number.

21210122210220 is a `hidden beast` number, since 2 + 1 + 210 + 1 + 22 + 210 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21210122210193 and 21210122210202.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 128276871 + ... + 128442110.

It is an arithmetic number, because the mean of its divisors is an integer number (490589974602).

Almost surely, 2^{21210122210220} is an apocalyptic number.

21210122210220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210122210220 is an abundant number, since it is smaller than the sum of its proper divisors (49434834132468).

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

21210122210220 is a wasteful number, since it uses less digits than its factorization.

21210122210220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256719022 (or 256719008 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21210122210220 its reverse (2201222101212), we get a palindrome (23411344311432).

The spelling of 21210122210220 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty-two million, two hundred ten thousand, two hundred twenty".