20210121202021 has 16 divisors (see below), whose sum is σ = 21440559772800. Its totient is φ = 19011563243200.

The previous prime is 20210121202013. The next prime is 20210121202081. The reversal of 20210121202021 is 12020212101202.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20210121202021 - 2³ = 20210121202013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20210121201986 and 20210121202004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20210121202081) 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, 28848535 + ... + 29540788.

It is an arithmetic number, because the mean of its divisors is an integer number (1340034985800).

Almost surely, 2^{20210121202021} is an apocalyptic number.

It is an amenable number.

20210121202021 is a deficient number, since it is larger than the sum of its proper divisors (1230438570779).

20210121202021 is a wasteful number, since it uses less digits than its factorization.

20210121202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58389596.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20210121202021 its reverse (12020212101202), we get a palindrome (32230333303223).

The spelling of 20210121202021 in words is "twenty trillion, two hundred ten billion, one hundred twenty-one million, two hundred two thousand, twenty-one".