1021012020020 has 48 divisors (see below), whose sum is σ = 2203956951168. Its totient is φ = 397027163520.

The previous prime is 1021012019969. The next prime is 1021012020023. The reversal of 1021012020020 is 200202101201.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1021012019983 and 1021012020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021012020023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 277409 + ... + 1455671.

It is an arithmetic number, because the mean of its divisors is an integer number (45915769816).

Almost surely, 2^{1021012020020} is an apocalyptic number.

1021012020020 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 1021012020020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1101978475584).

1021012020020 is an abundant number, since it is smaller than the sum of its proper divisors (1182944931148).

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

1021012020020 is a wasteful number, since it uses less digits than its factorization.

1021012020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1179480 (or 1179478 counting only the distinct ones).

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

Adding to 1021012020020 its reverse (200202101201), we get a palindrome (1221214121221).

The spelling of 1021012020020 in words is "one trillion, twenty-one billion, twelve million, twenty thousand, twenty".