1311221120220 has 72 divisors (see below), whose sum is σ = 4338949895280. Its totient is φ = 317871786240.

The previous prime is 1311221120219. The next prime is 1311221120243. The reversal of 1311221120220 is 220211221131.

1311221120220 is a `hidden beast` number, since 1 + 311 + 22 + 112 + 0 + 220 = 666.

It is a super-2 number, since 2×1311221120220² (a number of 25 digits) contains 22 as substring.

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 = 1311221120193 and 1311221120202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 331114465 + ... + 331118424.

It is an arithmetic number, because the mean of its divisors is an integer number (60263192990).

Almost surely, 2^{1311221120220} is an apocalyptic number.

1311221120220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311221120220 is an abundant number, since it is smaller than the sum of its proper divisors (3027728775060).

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

1311221120220 is a wasteful number, since it uses less digits than its factorization.

1311221120220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662232915 (or 662232910 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 1311221120220 its reverse (220211221131), we get a palindrome (1531432341351).

The spelling of 1311221120220 in words is "one trillion, three hundred eleven billion, two hundred twenty-one million, one hundred twenty thousand, two hundred twenty".