1221020221210 has 16 divisors (see below), whose sum is σ = 2198006702496. Its totient is φ = 488370243088.

The previous prime is 1221020221163. The next prime is 1221020221219. The reversal of 1221020221210 is 121220201221.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1221020221219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4594984 + ... + 4853443.

It is an arithmetic number, because the mean of its divisors is an integer number (137375418906).

Almost surely, 2^{1221020221210} is an apocalyptic number.

1221020221210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221020221210 is a deficient number, since it is larger than the sum of its proper divisors (976986481286).

1221020221210 is a wasteful number, since it uses less digits than its factorization.

1221020221210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9461357.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221020221210 its reverse (121220201221), we get a palindrome (1342240422431).

The spelling of 1221020221210 in words is "one trillion, two hundred twenty-one billion, twenty million, two hundred twenty-one thousand, two hundred ten".