1111212121220 has 12 divisors (see below), whose sum is σ = 2333545454604. Its totient is φ = 444484848480.

The previous prime is 1111212121199. The next prime is 1111212121273. The reversal of 1111212121220 is 221212121111.

It can be written as a sum of positive squares in 2 ways, for example, as 141979747204 + 969232374016 = 376802^2 + 984496^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27780303011 + ... + 27780303050.

It is an arithmetic number, because the mean of its divisors is an integer number (194462121217).

Almost surely, 2^{1111212121220} is an apocalyptic number.

1111212121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1111212121220 is an abundant number, since it is smaller than the sum of its proper divisors (1222333333384).

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

1111212121220 is a wasteful number, since it uses less digits than its factorization.

1111212121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55560606070 (or 55560606068 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1111212121220 its reverse (221212121111), we get a palindrome (1332424242331).

The spelling of 1111212121220 in words is "one trillion, one hundred eleven billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty".