10001220121 has 2 divisors, whose sum is σ = 10001220122. Its totient is φ = 10001220120.

The previous prime is 10001220113. The next prime is 10001220143. The reversal of 10001220121 is 12102210001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8438994496 + 1562225625 = 91864^2 + 39525^2 .

It is a cyclic number.

It is not a de Polignac number, because 10001220121 - 2³ = 10001220113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 10001220098 and 10001220107.

It is not a weakly prime, because it can be changed into another prime (10001220421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5000610060 + 5000610061.

It is an arithmetic number, because the mean of its divisors is an integer number (5000610061).

Almost surely, 2^10001220121 is an apocalyptic number.

It is an amenable number.

10001220121 is a deficient number, since it is larger than the sum of its proper divisors (1).

10001220121 is an equidigital number, since it uses as much as digits as its factorization.

10001220121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 10001220121 its reverse (12102210001), we get a palindrome (22103430122).

The spelling of 10001220121 in words is "ten billion, one million, two hundred twenty thousand, one hundred twenty-one".