2121121220 has 12 divisors (see below), whose sum is σ = 4454354604. Its totient is φ = 848448480.

The previous prime is 2121121217. The next prime is 2121121231. The reversal of 2121121220 is 221211212.

It can be written as a sum of positive squares in 2 ways, for example, as 238949764 + 1882171456 = 15458^2 + 43384^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2121121195 and 2121121204.

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, 53028011 + ... + 53028050.

It is an arithmetic number, because the mean of its divisors is an integer number (371196217).

Almost surely, 2^2121121220 is an apocalyptic number.

2121121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121121220 is an abundant number, since it is smaller than the sum of its proper divisors (2333233384).

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

2121121220 is a wasteful number, since it uses less digits than its factorization.

2121121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106056070 (or 106056068 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2121121220 is about 46055.6317946025. The cubic root of 2121121220 is about 1284.8580886650.

Adding to 2121121220 its reverse (221211212), we get a palindrome (2342332432).

The spelling of 2121121220 in words is "two billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty".