201211121220 has 24 divisors (see below), whose sum is σ = 563391139584. Its totient is φ = 53656298976.

The previous prime is 201211121179. The next prime is 201211121227. The reversal of 201211121220 is 22121112102.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 201211121220.

It is not an unprimeable number, because it can be changed into a prime (201211121227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1676759284 + ... + 1676759403.

It is an arithmetic number, because the mean of its divisors is an integer number (23474630816).

Almost surely, 2^201211121220 is an apocalyptic number.

201211121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201211121220 is an abundant number, since it is smaller than the sum of its proper divisors (362180018364).

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

201211121220 is a wasteful number, since it uses less digits than its factorization.

201211121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3353518699 (or 3353518697 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 201211121220 its reverse (22121112102), we get a palindrome (223332233322).

The spelling of 201211121220 in words is "two hundred one billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty".