1211220221020 has 24 divisors (see below), whose sum is σ = 2654152137504. Its totient is φ = 463423388736.

The previous prime is 1211220220999. The next prime is 1211220221021. The reversal of 1211220221020 is 201220221121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1211220220985 and 1211220221003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211220221021) 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, 1316543259 + ... + 1316544178.

It is an arithmetic number, because the mean of its divisors is an integer number (110589672396).

Almost surely, 2^{1211220221020} is an apocalyptic number.

1211220221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211220221020 is an abundant number, since it is smaller than the sum of its proper divisors (1442931916484).

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

1211220221020 is a wasteful number, since it uses less digits than its factorization.

1211220221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2633087469 (or 2633087467 counting only the distinct ones).

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

Adding to 1211220221020 its reverse (201220221121), we get a palindrome (1412440442141).

The spelling of 1211220221020 in words is "one trillion, two hundred eleven billion, two hundred twenty million, two hundred twenty-one thousand, twenty".