20101210221 has 16 divisors (see below), whose sum is σ = 27545984000. Its totient is φ = 13033685808.

The previous prime is 20101210169. The next prime is 20101210223. The reversal of 20101210221 is 12201210102.

It is not a de Polignac number, because 20101210221 - 2¹⁰ = 20101209197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20101210197 and 20101210206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101210223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 617071 + ... + 648828.

It is an arithmetic number, because the mean of its divisors is an integer number (1721624000).

Almost surely, 2^20101210221 is an apocalyptic number.

It is an amenable number.

20101210221 is a deficient number, since it is larger than the sum of its proper divisors (7444773779).

20101210221 is a wasteful number, since it uses less digits than its factorization.

20101210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266048.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20101210221 its reverse (12201210102), we get a palindrome (32302420323).

The spelling of 20101210221 in words is "twenty billion, one hundred one million, two hundred ten thousand, two hundred twenty-one".