1221001222220 has 48 divisors (see below), whose sum is σ = 2799167861280. Its totient is φ = 444655443456.

The previous prime is 1221001222211. The next prime is 1221001222229. The reversal of 1221001222220 is 222221001221.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1221001222211) and next prime (1221001222229).

It is not an unprimeable number, because it can be changed into a prime (1221001222229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32146490 + ... + 32184449.

It is an arithmetic number, because the mean of its divisors is an integer number (58315997110).

Almost surely, 2^{1221001222220} is an apocalyptic number.

1221001222220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221001222220 is an abundant number, since it is smaller than the sum of its proper divisors (1578166639060).

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

1221001222220 is a wasteful number, since it uses less digits than its factorization.

1221001222220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64331034 (or 64331032 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 1221001222220 its reverse (222221001221), we get a palindrome (1443222223441).

The spelling of 1221001222220 in words is "one trillion, two hundred twenty-one billion, one million, two hundred twenty-two thousand, two hundred twenty".