2121001021020 has 384 divisors, whose sum is σ = 7177679308800. Its totient is φ = 457870049280.

The previous prime is 2121001020991. The next prime is 2121001021033. The reversal of 2121001021020 is 201201001212.

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 = 2121001020987 and 2121001021005.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 83659306 + ... + 83684654.

It is an arithmetic number, because the mean of its divisors is an integer number (18691873200).

Almost surely, 2^{2121001021020} is an apocalyptic number.

2121001021020 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 2121001021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3588839654400).

2121001021020 is an abundant number, since it is smaller than the sum of its proper divisors (5056678287780).

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

2121001021020 is a wasteful number, since it uses less digits than its factorization.

2121001021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25565 (or 25563 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 2121001021020 its reverse (201201001212), we get a palindrome (2322202022232).

The spelling of 2121001021020 in words is "two trillion, one hundred twenty-one billion, one million, twenty-one thousand, twenty".