221121210001 has 2 divisors, whose sum is σ = 221121210002. Its totient is φ = 221121210000.

The previous prime is 221121209987. The next prime is 221121210043. The reversal of 221121210001 is 100012121122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 218476782225 + 2644427776 = 467415^2 + 51424^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121210001 - 2⁹ = 221121209489 is a prime.

It is not a weakly prime, because it can be changed into another prime (221121210071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560605000 + 110560605001.

It is an arithmetic number, because the mean of its divisors is an integer number (110560605001).

Almost surely, 2^221121210001 is an apocalyptic number.

It is an amenable number.

221121210001 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121210001 is an equidigital number, since it uses as much as digits as its factorization.

221121210001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 221121210001 its reverse (100012121122), we get a palindrome (321133331123).

The spelling of 221121210001 in words is "two hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, one".