10001221112021 has 4 divisors (see below), whose sum is σ = 10003248528492. Its totient is φ = 9999193695552.

The previous prime is 10001221112011. The next prime is 10001221112041. The reversal of 10001221112021 is 12021112210001.

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 3451844431396 + 6549376680625 = 1857914^2 + 2559175^2 .

It is a cyclic number.

It is not a de Polignac number, because 10001221112021 - 2³⁰ = 10000147370197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10001221111987 and 10001221112005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10001221112011) 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, 1013700836 + ... + 1013710701.

It is an arithmetic number, because the mean of its divisors is an integer number (2500812132123).

Almost surely, 2^{10001221112021} is an apocalyptic number.

It is an amenable number.

10001221112021 is a deficient number, since it is larger than the sum of its proper divisors (2027416471).

10001221112021 is an equidigital number, since it uses as much as digits as its factorization.

10001221112021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2027416470.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 10001221112021 its reverse (12021112210001), we get a palindrome (22022333322022).

The spelling of 10001221112021 in words is "ten trillion, one billion, two hundred twenty-one million, one hundred twelve thousand, twenty-one".