1011221020020 has 96 divisors (see below), whose sum is σ = 2874262487040. Its totient is φ = 265589038080.

The previous prime is 1011221019983. The next prime is 1011221020067. The reversal of 1011221020020 is 200201221101.

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 = 1011221019978 and 1011221020005.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2942605 + ... + 3268235.

It is an arithmetic number, because the mean of its divisors is an integer number (29940234240).

Almost surely, 2^{1011221020020} is an apocalyptic number.

1011221020020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1011221020020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1437131243520).

1011221020020 is an abundant number, since it is smaller than the sum of its proper divisors (1863041467020).

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

1011221020020 is a wasteful number, since it uses less digits than its factorization.

1011221020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326425 (or 326423 counting only the distinct ones).

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

Adding to 1011221020020 its reverse (200201221101), we get a palindrome (1211422241121).

The spelling of 1011221020020 in words is "one trillion, eleven billion, two hundred twenty-one million, twenty thousand, twenty".