2001022001020 has 96 divisors (see below), whose sum is σ = 4850831051136. Its totient is φ = 679155840000.

The previous prime is 2001022001009. The next prime is 2001022001023. The reversal of 2001022001020 is 201002201002.

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 = 2001022000988 and 2001022001006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001022001023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139992994 + ... + 140007286.

It is an arithmetic number, because the mean of its divisors is an integer number (50529490116).

Almost surely, 2^{2001022001020} is an apocalyptic number.

2001022001020 is a gapful number since it is divisible by the number (20) 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 2001022001020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2425415525568).

2001022001020 is an abundant number, since it is smaller than the sum of its proper divisors (2849809050116).

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

2001022001020 is a wasteful number, since it uses less digits than its factorization.

2001022001020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24311 (or 24309 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 2001022001020 its reverse (201002201002), we get a palindrome (2202024202022).

The spelling of 2001022001020 in words is "two trillion, one billion, twenty-two million, one thousand, twenty".