2101221022121 has 8 divisors (see below), whose sum is σ = 2286181795464. Its totient is φ = 1919592875520.

The previous prime is 2101221022097. The next prime is 2101221022127. The reversal of 2101221022121 is 1212201221012.

It can be written as a sum of positive squares in 4 ways, for example, as 585318333721 + 1515902688400 = 765061^2 + 1231220^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2101221022121 is a prime.

It is a Duffinian number.

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 2101221022121.

It is not an unprimeable number, because it can be changed into a prime (2101221022127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 833155370 + ... + 833157891.

It is an arithmetic number, because the mean of its divisors is an integer number (285772724433).

Almost surely, 2^{2101221022121} is an apocalyptic number.

It is an amenable number.

2101221022121 is a deficient number, since it is larger than the sum of its proper divisors (184960773343).

2101221022121 is a wasteful number, since it uses less digits than its factorization.

2101221022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1666313371.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2101221022121 its reverse (1212201221012), we get a palindrome (3313422243133).

The spelling of 2101221022121 in words is "two trillion, one hundred one billion, two hundred twenty-one million, twenty-two thousand, one hundred twenty-one".