1021121220 has 48 divisors (see below), whose sum is σ = 3267589248. Its totient is φ = 233399040.

The previous prime is 1021121209. The next prime is 1021121243. The reversal of 1021121220 is 221211201.

1021121220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×1021121220³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1021121196 and 1021121205.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1215201 + ... + 1216040.

It is an arithmetic number, because the mean of its divisors is an integer number (68074776).

Almost surely, 2^1021121220 is an apocalyptic number.

1021121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021121220 is an abundant number, since it is smaller than the sum of its proper divisors (2246468028).

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

1021121220 is a wasteful number, since it uses less digits than its factorization.

1021121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2431260 (or 2431258 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1021121220 is about 31954.9874041596. The cubic root of 1021121220 is about 1006.9914128993.

Adding to 1021121220 its reverse (221211201), we get a palindrome (1242332421).

The spelling of 1021121220 in words is "one billion, twenty-one million, one hundred twenty-one thousand, two hundred twenty".