1021221120020 has 48 divisors (see below), whose sum is σ = 2230009986960. Its totient is φ = 392359059456.

The previous prime is 1021221120011. The next prime is 1021221120043. The reversal of 1021221120020 is 200211221201.

It can be written as a sum of positive squares in 8 ways, for example, as 179704775056 + 841516344964 = 423916^2 + 917342^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1021221119977 and 1021221120004.

It is a congruent number.

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, 4449527 + ... + 4673406.

It is an arithmetic number, because the mean of its divisors is an integer number (46458541395).

Almost surely, 2^{1021221120020} is an apocalyptic number.

1021221120020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021221120020 is an abundant number, since it is smaller than the sum of its proper divisors (1208788866940).

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

1021221120020 is a wasteful number, since it uses less digits than its factorization.

1021221120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9123164 (or 9123162 counting only the distinct ones).

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

Adding to 1021221120020 its reverse (200211221201), we get a palindrome (1221432341221).

The spelling of 1021221120020 in words is "one trillion, twenty-one billion, two hundred twenty-one million, one hundred twenty thousand, twenty".