1021221020 has 12 divisors (see below), whose sum is σ = 2144564184. Its totient is φ = 408488400.

The previous prime is 1021220969. The next prime is 1021221041. The reversal of 1021221020 is 201221201.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1021220992 and 1021221010.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25530506 + ... + 25530545.

It is an arithmetic number, because the mean of its divisors is an integer number (178713682).

Almost surely, 2^1021221020 is an apocalyptic number.

1021221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021221020 is an abundant number, since it is smaller than the sum of its proper divisors (1123343164).

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

1021221020 is a wasteful number, since it uses less digits than its factorization.

1021221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51061060 (or 51061058 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1021221020 is about 31956.5489375809. The cubic root of 1021221020 is about 1007.0242181683.

Adding to 1021221020 its reverse (201221201), we get a palindrome (1222442221).

The spelling of 1021221020 in words is "one billion, twenty-one million, two hundred twenty-one thousand, twenty".