1220121122220 has 576 divisors, whose sum is σ = 4990719412224. Its totient is φ = 233016791040.

The previous prime is 1220121122191. The next prime is 1220121122261. The reversal of 1220121122220 is 222211210221.

It is a happy number.

1220121122220 is a `hidden beast` number, since 12 + 201 + 211 + 22 + 220 = 666.

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 = 1220121122193 and 1220121122202.

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 41967409 + ... + 41996471.

It is an arithmetic number, because the mean of its divisors is an integer number (8664443424).

Almost surely, 2^{1220121122220} is an apocalyptic number.

1220121122220 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 1220121122220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2495359706112).

1220121122220 is an abundant number, since it is smaller than the sum of its proper divisors (3770598290004).

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

1220121122220 is a wasteful number, since it uses less digits than its factorization.

1220121122220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29342 (or 29337 counting only the distinct ones).

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

Adding to 1220121122220 its reverse (222211210221), we get a palindrome (1442332332441).

It can be divided in two parts, 1220121 and 122220, that added together give a triangular number (1342341 = T₁₆₃₈).

The spelling of 1220121122220 in words is "one trillion, two hundred twenty billion, one hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty".