20011021212121 has 16 divisors (see below), whose sum is σ = 20915840736000. Its totient is φ = 19109125623808.

The previous prime is 20011021212103. The next prime is 20011021212137. The reversal of 20011021212121 is 12121212011002.

It is a cyclic number.

It is not a de Polignac number, because 20011021212121 - 2¹¹ = 20011021210073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20011021212095 and 20011021212104.

It is not an unprimeable number, because it can be changed into a prime (20011021213121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33700620 + ... + 34289266.

It is an arithmetic number, because the mean of its divisors is an integer number (1307240046000).

Almost surely, 2^{20011021212121} is an apocalyptic number.

It is an amenable number.

20011021212121 is a deficient number, since it is larger than the sum of its proper divisors (904819523879).

20011021212121 is a wasteful number, since it uses less digits than its factorization.

20011021212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591128.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20011021212121 its reverse (12121212011002), we get a palindrome (32132233223123).

The spelling of 20011021212121 in words is "twenty trillion, eleven billion, twenty-one million, two hundred twelve thousand, one hundred twenty-one".