1221012102220 has 24 divisors (see below), whose sum is σ = 2565352944000. Its totient is φ = 488171025792.

The previous prime is 1221012102173. The next prime is 1221012102227. The reversal of 1221012102220 is 222012101221.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1221012102194 and 1221012102203.

It is not an unprimeable number, because it can be changed into a prime (1221012102227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14570620 + ... + 14654179.

It is an arithmetic number, because the mean of its divisors is an integer number (106889706000).

Almost surely, 2^{1221012102220} is an apocalyptic number.

1221012102220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221012102220 is an abundant number, since it is smaller than the sum of its proper divisors (1344340841780).

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

1221012102220 is a wasteful number, since it uses less digits than its factorization.

1221012102220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29226897 (or 29226895 counting only the distinct ones).

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

Adding to 1221012102220 its reverse (222012101221), we get a palindrome (1443024203441).

Subtracting from 1221012102220 its reverse (222012101221), we obtain a palindrome (999000000999).

The spelling of 1221012102220 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred two thousand, two hundred twenty".