20102121221 has 16 divisors (see below), whose sum is σ = 25160419200. Its totient is φ = 15635395008.

The previous prime is 20102121181. The next prime is 20102121227. The reversal of 20102121221 is 12212120102.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20102121221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20102121196 and 20102121205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102121227) 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, 1866686 + ... + 1877423.

It is an arithmetic number, because the mean of its divisors is an integer number (1572526200).

Almost surely, 2^20102121221 is an apocalyptic number.

It is an amenable number.

20102121221 is a deficient number, since it is larger than the sum of its proper divisors (5058297979).

20102121221 is a wasteful number, since it uses less digits than its factorization.

20102121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3744188.

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

Adding to 20102121221 its reverse (12212120102), we get a palindrome (32314241323).

The spelling of 20102121221 in words is "twenty billion, one hundred two million, one hundred twenty-one thousand, two hundred twenty-one".