2021001122221 has 4 divisors (see below), whose sum is σ = 2021151094972. Its totient is φ = 2020851149472.

The previous prime is 2021001122183. The next prime is 2021001122237. The reversal of 2021001122221 is 1222211001202.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1733801594121 + 287199528100 = 1316739^2 + 535910^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021001122221 - 2¹⁵ = 2021001089453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021001122195 and 2021001122204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021001132221) 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, 74966160 + ... + 74993113.

It is an arithmetic number, because the mean of its divisors is an integer number (505287773743).

Almost surely, 2^{2021001122221} is an apocalyptic number.

It is an amenable number.

2021001122221 is a deficient number, since it is larger than the sum of its proper divisors (149972751).

2021001122221 is a wasteful number, since it uses less digits than its factorization.

2021001122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149972750.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2021001122221 its reverse (1222211001202), we get a palindrome (3243212123423).

The spelling of 2021001122221 in words is "two trillion, twenty-one billion, one million, one hundred twenty-two thousand, two hundred twenty-one".