20121202221 has 4 divisors (see below), whose sum is σ = 26828269632. Its totient is φ = 13414134812.

The previous prime is 20121202207. The next prime is 20121202223. The reversal of 20121202221 is 12220212102.

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 20121202221 - 2⁷ = 20121202093 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20121202221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121202223) 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, 3353533701 + ... + 3353533706.

It is an arithmetic number, because the mean of its divisors is an integer number (6707067408).

Almost surely, 2^20121202221 is an apocalyptic number.

It is an amenable number.

20121202221 is a deficient number, since it is larger than the sum of its proper divisors (6707067411).

20121202221 is an equidigital number, since it uses as much as digits as its factorization.

20121202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6707067410.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 20121202221 its reverse (12220212102), we get a palindrome (32341414323).

The spelling of 20121202221 in words is "twenty billion, one hundred twenty-one million, two hundred two thousand, two hundred twenty-one".