21201220110210 has 128 divisors (see below), whose sum is σ = 60221209466880. Its totient is φ = 4676267828736.

The previous prime is 21201220110181. The next prime is 21201220110211. The reversal of 21201220110210 is 1201102210212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21201220110210.

It is not an unprimeable number, because it can be changed into a prime (21201220110211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13394275 + ... + 14893254.

It is an arithmetic number, because the mean of its divisors is an integer number (470478198960).

Almost surely, 2^{21201220110210} is an apocalyptic number.

21201220110210 is an abundant number, since it is smaller than the sum of its proper divisors (39019989356670).

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

21201220110210 is a wasteful number, since it uses less digits than its factorization.

21201220110210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28287672.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21201220110210 its reverse (1201102210212), we get a palindrome (22402322320422).

The spelling of 21201220110210 in words is "twenty-one trillion, two hundred one billion, two hundred twenty million, one hundred ten thousand, two hundred ten".