1001111012020 has 432 divisors, whose sum is σ = 2800963625040. Its totient is φ = 298270629888.

The previous prime is 1001111012009. The next prime is 1001111012059. The reversal of 1001111012020 is 202101111001.

It can be written as a sum of positive squares in 8 ways, for example, as 64218655396 + 936892356624 = 253414^2 + 967932^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1001111011988 and 1001111012006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 255579102 + ... + 255583018.

It is an arithmetic number, because the mean of its divisors is an integer number (6483712095).

Almost surely, 2^{1001111012020} is an apocalyptic number.

1001111012020 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 1001111012020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1400481812520).

1001111012020 is an abundant number, since it is smaller than the sum of its proper divisors (1799852613020).

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

1001111012020 is a wasteful number, since it uses less digits than its factorization.

1001111012020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4032 (or 4000 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 1001111012020 its reverse (202101111001), we get a palindrome (1203212123021).

The spelling of 1001111012020 in words is "one trillion, one billion, one hundred eleven million, twelve thousand, twenty".