211121211121220 has 24 divisors (see below), whose sum is σ = 444174052699608. Its totient is φ = 84292387430400.

The previous prime is 211121211121211. The next prime is 211121211121243. The reversal of 211121211121220 is 22121112121112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3838848652804 + 207282362468416 = 1959298^2 + 14397304^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 211121211121192 and 211121211121201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9756052541 + ... + 9756074180.

It is an arithmetic number, because the mean of its divisors is an integer number (18507252195817).

Almost surely, 2^{211121211121220} is an apocalyptic number.

211121211121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211121211121220 is an abundant number, since it is smaller than the sum of its proper divisors (233052841578388).

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

211121211121220 is a wasteful number, since it uses less digits than its factorization.

211121211121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19512127271 (or 19512127269 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 211121211121220 its reverse (22121112121112), we get a palindrome (233242323242332).

The spelling of 211121211121220 in words is "two hundred eleven trillion, one hundred twenty-one billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty".