11211211121220 has 72 divisors (see below), whose sum is σ = 37098916807680. Its totient is φ = 2717869362240.

The previous prime is 11211211121183. The next prime is 11211211121309. The reversal of 11211211121220 is 2212111211211.

It is a happy number.

11211211121220 is a `hidden beast` number, since 1 + 1 + 211 + 211 + 1 + 21 + 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 = 11211211121193 and 11211211121202.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2831111940 + ... + 2831115899.

It is an arithmetic number, because the mean of its divisors is an integer number (515262733440).

Almost surely, 2^{11211211121220} is an apocalyptic number.

11211211121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11211211121220 is an abundant number, since it is smaller than the sum of its proper divisors (25887705686460).

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

11211211121220 is a wasteful number, since it uses less digits than its factorization.

11211211121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5662227865 (or 5662227860 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 11211211121220 its reverse (2212111211211), we get a palindrome (13423322332431).

The spelling of 11211211121220 in words is "eleven trillion, two hundred eleven billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty".