20101001221 has 4 divisors (see below), whose sum is σ = 22972572832. Its totient is φ = 17229429612.

The previous prime is 20101001209. The next prime is 20101001257. The reversal of 20101001221 is 12210010102.

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 20101001221 - 2¹¹ = 20100999173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20101001198 and 20101001207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101001201) 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, 1435785795 + ... + 1435785808.

It is an arithmetic number, because the mean of its divisors is an integer number (5743143208).

Almost surely, 2^20101001221 is an apocalyptic number.

It is an amenable number.

20101001221 is a deficient number, since it is larger than the sum of its proper divisors (2871571611).

20101001221 is an equidigital number, since it uses as much as digits as its factorization.

20101001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2871571610.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20101001221 its reverse (12210010102), we get a palindrome (32311011323).

The spelling of 20101001221 in words is "twenty billion, one hundred one million, one thousand, two hundred twenty-one".