2100002020020 has 72 divisors (see below), whose sum is σ = 6376804938504. Its totient is φ = 559402841088.

The previous prime is 2100002020009. The next prime is 2100002020027. The reversal of 2100002020020 is 200202000012.

It can be written as a sum of positive squares in 4 ways, for example, as 106721129124 + 1993280890896 = 326682^2 + 1411836^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 2100002019984 and 2100002020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100002020027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6056889 + ... + 6394208.

It is an arithmetic number, because the mean of its divisors is an integer number (88566735257).

Almost surely, 2^{2100002020020} is an apocalyptic number.

2100002020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100002020020 is an abundant number, since it is smaller than the sum of its proper divisors (4276802918484).

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

2100002020020 is a wasteful number, since it uses less digits than its factorization.

2100002020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12452049 (or 12452044 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

Adding to 2100002020020 its reverse (200202000012), we get a palindrome (2300204020032).

The spelling of 2100002020020 in words is "two trillion, one hundred billion, two million, twenty thousand, twenty".