1212211121220 has 144 divisors (see below), whose sum is σ = 4037882808960. Its totient is φ = 291923136000.

The previous prime is 1212211121203. The next prime is 1212211121237. The reversal of 1212211121220 is 221211122121.

1212211121220 is a `hidden beast` number, since 1 + 212 + 211 + 1 + 21 + 220 = 666.

It is an interprime number because it is at equal distance from previous prime (1212211121203) and next prime (1212211121237).

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 = 1212211121193 and 1212211121202.

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 47 ways as a sum of consecutive naturals, for example, 1728265 + ... + 2326224.

It is an arithmetic number, because the mean of its divisors is an integer number (28040852840).

Almost surely, 2^{1212211121220} is an apocalyptic number.

1212211121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212211121220 is an abundant number, since it is smaller than the sum of its proper divisors (2825671687740).

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

1212211121220 is a wasteful number, since it uses less digits than its factorization.

1212211121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4054666 (or 4054661 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212211121220 its reverse (221211122121), we get a palindrome (1433422243341).

Subtracting from 1212211121220 its reverse (221211122121), we obtain a palindrome (990999999099).

The spelling of 1212211121220 in words is "one trillion, two hundred twelve billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty".