21020221012121 has 8 divisors (see below), whose sum is σ = 21022912190400. Its totient is φ = 21017530038960.

The previous prime is 21020221012097. The next prime is 21020221012157. The reversal of 21020221012121 is 12121012202012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020221012121 is a prime.

It is a super-3 number, since 3×21020221012121³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21020221012121.

It is not an unprimeable number, because it can be changed into a prime (21020221012421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 313042211 + ... + 313109351.

It is an arithmetic number, because the mean of its divisors is an integer number (2627864023800).

Almost surely, 2^{21020221012121} is an apocalyptic number.

It is an amenable number.

21020221012121 is a deficient number, since it is larger than the sum of its proper divisors (2691178279).

21020221012121 is a wasteful number, since it uses less digits than its factorization.

21020221012121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102559.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21020221012121 its reverse (12121012202012), we get a palindrome (33141233214133).

The spelling of 21020221012121 in words is "twenty-one trillion, twenty billion, two hundred twenty-one million, twelve thousand, one hundred twenty-one".