1221000222210 has 64 divisors (see below), whose sum is σ = 3113460633600. Its totient is φ = 305580364992.

The previous prime is 1221000222181. The next prime is 1221000222217. The reversal of 1221000222210 is 122220001221.

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 1221000222210.

It is not an unprimeable number, because it can be changed into a prime (1221000222217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9948850 + ... + 10070829.

It is an arithmetic number, because the mean of its divisors is an integer number (48647822400).

Almost surely, 2^{1221000222210} is an apocalyptic number.

1221000222210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221000222210 is an abundant number, since it is smaller than the sum of its proper divisors (1892460411390).

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

1221000222210 is a wasteful number, since it uses less digits than its factorization.

1221000222210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20019815.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 1221000222210 its reverse (122220001221), we get a palindrome (1343220223431).

The spelling of 1221000222210 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two thousand, two hundred ten".