1221000000220 has 96 divisors (see below), whose sum is σ = 3442707749376. Its totient is φ = 351296697600.

The previous prime is 1221000000217. The next prime is 1221000000221. The reversal of 1221000000220 is 220000001221.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1221000000197 and 1221000000206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000000221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30474486 + ... + 30514525.

It is an arithmetic number, because the mean of its divisors is an integer number (35861539056).

Almost surely, 2^{1221000000220} is an apocalyptic number.

1221000000220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221000000220 is an abundant number, since it is smaller than the sum of its proper divisors (2221707749156).

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

1221000000220 is a wasteful number, since it uses less digits than its factorization.

1221000000220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60989051 (or 60989049 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 1221000000220 its reverse (220000001221), we get a palindrome (1441000001441).

The spelling of 1221000000220 in words is "one trillion, two hundred twenty-one billion, two hundred twenty", and thus it is an aban number.