10000021221221 has 4 divisors (see below), whose sum is σ = 10003669535244. Its totient is φ = 9996372907200.

The previous prime is 10000021221187. The next prime is 10000021221233. The reversal of 10000021221221 is 12212212000001.

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 3563581185025 + 6436440036196 = 1887745^2 + 2537014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10000021221221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10000021221196 and 10000021221205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10000021221271) 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, 1824152900 + ... + 1824158381.

It is an arithmetic number, because the mean of its divisors is an integer number (2500917383811).

Almost surely, 2^{10000021221221} is an apocalyptic number.

It is an amenable number.

10000021221221 is a deficient number, since it is larger than the sum of its proper divisors (3648314023).

10000021221221 is an equidigital number, since it uses as much as digits as its factorization.

10000021221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3648314022.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 10000021221221 its reverse (12212212000001), we get a palindrome (22212233221222).

The spelling of 10000021221221 in words is "ten trillion, twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".