1021111111020 has 288 divisors, whose sum is σ = 3859901821440. Its totient is φ = 195857326080.

The previous prime is 1021111111001. The next prime is 1021111111099. The reversal of 1021111111020 is 201111111201.

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 = 1021111110987 and 1021111111005.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 126876 + ... + 1434684.

It is an arithmetic number, because the mean of its divisors is an integer number (13402436880).

Almost surely, 2^{1021111111020} is an apocalyptic number.

1021111111020 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 1021111111020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1929950910720).

1021111111020 is an abundant number, since it is smaller than the sum of its proper divisors (2838790710420).

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

1021111111020 is a wasteful number, since it uses less digits than its factorization.

1021111111020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1307865 (or 1307850 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 1021111111020 its reverse (201111111201), we get a palindrome (1222222222221).

The spelling of 1021111111020 in words is "one trillion, twenty-one billion, one hundred eleven million, one hundred eleven thousand, twenty".