1221222211020 has 240 divisors, whose sum is σ = 4421661507648. Its totient is φ = 276372518400.

The previous prime is 1221222211003. The next prime is 1221222211021. The reversal of 1221222211020 is 201122221221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1221222210984 and 1221222211002.

It is not an unprimeable number, because it can be changed into a prime (1221222211021) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 612214 + ... + 1678466.

Almost surely, 2^{1221222211020} is an apocalyptic number.

1221222211020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221222211020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2210830753824).

1221222211020 is an abundant number, since it is smaller than the sum of its proper divisors (3200439296628).

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

1221222211020 is a wasteful number, since it uses less digits than its factorization.

1221222211020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066382 (or 1066371 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1221222211020 its reverse (201122221221), we get a palindrome (1422344432241).

The spelling of 1221222211020 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred eleven thousand, twenty".