2121101110021 has 8 divisors (see below), whose sum is σ = 2134870761080. Its totient is φ = 2107334743488.

The previous prime is 2121101110019. The next prime is 2121101110109. The reversal of 2121101110021 is 1200111011212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 291723132996 + 1829377977025 = 540114^2 + 1352545^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2121101110021 - 2¹ = 2121101110019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121101109983 and 2121101110010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121101140021) 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, 481315 + ... + 2115151.

It is an arithmetic number, because the mean of its divisors is an integer number (266858845135).

Almost surely, 2^{2121101110021} is an apocalyptic number.

It is an amenable number.

2121101110021 is a deficient number, since it is larger than the sum of its proper divisors (13769651059).

2121101110021 is a wasteful number, since it uses less digits than its factorization.

2121101110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1642263.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 2121101110021 its reverse (1200111011212), we get a palindrome (3321212121233).

The spelling of 2121101110021 in words is "two trillion, one hundred twenty-one billion, one hundred one million, one hundred ten thousand, twenty-one".