20010122221 has 4 divisors (see below), whose sum is σ = 21187188252. Its totient is φ = 18833056192.

The previous prime is 20010122189. The next prime is 20010122261. The reversal of 20010122221 is 12222101002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12222101002 = 2 ⋅6111050501.

It can be written as a sum of positive squares in 2 ways, for example, as 6229944900 + 13780177321 = 78930^2 + 117389^2 .

It is a cyclic number.

It is not a de Polignac number, because 20010122221 - 2⁵ = 20010122189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010122261) 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, 588532990 + ... + 588533023.

It is an arithmetic number, because the mean of its divisors is an integer number (5296797063).

Almost surely, 2^20010122221 is an apocalyptic number.

It is an amenable number.

20010122221 is a deficient number, since it is larger than the sum of its proper divisors (1177066031).

20010122221 is a wasteful number, since it uses less digits than its factorization.

20010122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177066030.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20010122221 its reverse (12222101002), we get a palindrome (32232223223).

The spelling of 20010122221 in words is "twenty billion, ten million, one hundred twenty-two thousand, two hundred twenty-one".