2121000121021 has 4 divisors (see below), whose sum is σ = 2121009762844. Its totient is φ = 2120990479200.

The previous prime is 2121000120997. The next prime is 2121000121049. The reversal of 2121000121021 is 1201210001212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 208894702500 + 1912105418521 = 457050^2 + 1382789^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121000121021 - 2⁹ = 2121000120509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121000120992 and 2121000121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121000125021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4483050 + ... + 4933531.

It is an arithmetic number, because the mean of its divisors is an integer number (530252440711).

Almost surely, 2^{2121000121021} is an apocalyptic number.

It is an amenable number.

2121000121021 is a deficient number, since it is larger than the sum of its proper divisors (9641823).

2121000121021 is an equidigital number, since it uses as much as digits as its factorization.

2121000121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9641822.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 2121000121021 its reverse (1201210001212), we get a palindrome (3322210122233).

The spelling of 2121000121021 in words is "two trillion, one hundred twenty-one billion, one hundred twenty-one thousand, twenty-one".