2101221011221 has 4 divisors (see below), whose sum is σ = 2140866690732. Its totient is φ = 2061575331712.

The previous prime is 2101221011213. The next prime is 2101221011261. The reversal of 2101221011221 is 1221101221012.

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 963958730596 + 1137262280625 = 981814^2 + 1066425^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101221011221 - 2³ = 2101221011213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2101221011195 and 2101221011204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101221011261) 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, 19822839676 + ... + 19822839781.

It is an arithmetic number, because the mean of its divisors is an integer number (535216672683).

Almost surely, 2^{2101221011221} is an apocalyptic number.

It is an amenable number.

2101221011221 is a deficient number, since it is larger than the sum of its proper divisors (39645679511).

2101221011221 is an equidigital number, since it uses as much as digits as its factorization.

2101221011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39645679510.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 2101221011221 its reverse (1221101221012), we get a palindrome (3322322232233).

The spelling of 2101221011221 in words is "two trillion, one hundred one billion, two hundred twenty-one million, eleven thousand, two hundred twenty-one".