221121210210 has 32 divisors (see below), whose sum is σ = 532294224192. Its totient is φ = 58787509440.

The previous prime is 221121210133. The next prime is 221121210217. The reversal of 221121210210 is 12012121122.

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 221121210210.

It is not an unprimeable number, because it can be changed into a prime (221121210217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11124069 + ... + 11143928.

It is an arithmetic number, because the mean of its divisors is an integer number (16634194506).

Almost surely, 2^221121210210 is an apocalyptic number.

221121210210 is an abundant number, since it is smaller than the sum of its proper divisors (311173013982).

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

221121210210 is a wasteful number, since it uses less digits than its factorization.

221121210210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22268338.

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

Adding to 221121210210 its reverse (12012121122), we get a palindrome (233133331332).

The spelling of 221121210210 in words is "two hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, two hundred ten".