20002121002121 has 4 divisors (see below), whose sum is σ = 20002134542544. Its totient is φ = 20002107461700.

The previous prime is 20002121002109. The next prime is 20002121002147. The reversal of 20002121002121 is 12120012120002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20002121002121 - 2¹⁸ = 20002120739977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20002121002096 and 20002121002105.

It is not an unprimeable number, because it can be changed into a prime (20002121002181) 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, 4238915 + ... + 7613976.

It is an arithmetic number, because the mean of its divisors is an integer number (5000533635636).

Almost surely, 2^{20002121002121} is an apocalyptic number.

It is an amenable number.

20002121002121 is a deficient number, since it is larger than the sum of its proper divisors (13540423).

20002121002121 is a wasteful number, since it uses less digits than its factorization.

20002121002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13540422.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20002121002121 its reverse (12120012120002), we get a palindrome (32122133122123).

The spelling of 20002121002121 in words is "twenty trillion, two billion, one hundred twenty-one million, two thousand, one hundred twenty-one".