20121303221 has 4 divisors (see below), whose sum is σ = 21180319200. Its totient is φ = 19062287244.

The previous prime is 20121303197. The next prime is 20121303263. The reversal of 20121303221 is 12230312102.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12230312102 = 2 ⋅6115156051.

It is not a de Polignac number, because 20121303221 - 2¹⁰ = 20121302197 is a prime.

It is a super-2 number, since 2×20121303221² (a number of 21 digits) contains 22 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 20121303221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121303271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 529507961 + ... + 529507998.

It is an arithmetic number, because the mean of its divisors is an integer number (5295079800).

Almost surely, 2^20121303221 is an apocalyptic number.

It is an amenable number.

20121303221 is a deficient number, since it is larger than the sum of its proper divisors (1059015979).

20121303221 is a wasteful number, since it uses less digits than its factorization.

20121303221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059015978.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 20121303221 its reverse (12230312102), we get a palindrome (32351615323).

The spelling of 20121303221 in words is "twenty billion, one hundred twenty-one million, three hundred three thousand, two hundred twenty-one".