1221002211220 has 24 divisors (see below), whose sum is σ = 2797205066208. Its totient is φ = 444000804000.

The previous prime is 1221002211173. The next prime is 1221002211227. The reversal of 1221002211220 is 221122001221.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1221002211194 and 1221002211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221002211227) 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, 2775004806 + ... + 2775005245.

It is an arithmetic number, because the mean of its divisors is an integer number (116550211092).

Almost surely, 2^{1221002211220} is an apocalyptic number.

1221002211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221002211220 is an abundant number, since it is smaller than the sum of its proper divisors (1576202854988).

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

1221002211220 is a wasteful number, since it uses less digits than its factorization.

1221002211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5550010071 (or 5550010069 counting only the distinct ones).

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

Adding to 1221002211220 its reverse (221122001221), we get a palindrome (1442124212441).

The spelling of 1221002211220 in words is "one trillion, two hundred twenty-one billion, two million, two hundred eleven thousand, two hundred twenty".