20021012101221 has 4 divisors (see below), whose sum is σ = 26694682801632. Its totient is φ = 13347341400812.

The previous prime is 20021012101187. The next prime is 20021012101229. The reversal of 20021012101221 is 12210121012002.

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 20021012101221 - 2³⁰ = 20019938359397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20021012101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021012101229) 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, 3336835350201 + ... + 3336835350206.

It is an arithmetic number, because the mean of its divisors is an integer number (6673670700408).

Almost surely, 2^{20021012101221} is an apocalyptic number.

It is an amenable number.

20021012101221 is a deficient number, since it is larger than the sum of its proper divisors (6673670700411).

20021012101221 is an equidigital number, since it uses as much as digits as its factorization.

20021012101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6673670700410.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20021012101221 its reverse (12210121012002), we get a palindrome (32231133113223).

The spelling of 20021012101221 in words is "twenty trillion, twenty-one billion, twelve million, one hundred one thousand, two hundred twenty-one".