221021112121001 has 2 divisors, whose sum is σ = 221021112121002. Its totient is φ = 221021112121000.

The previous prime is 221021112120943. The next prime is 221021112121009. The reversal of 221021112121001 is 100121211120122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218574077631001 + 2447034490000 = 14784251^2 + 1564300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221021112121001 is a prime.

It is not a weakly prime, because it can be changed into another prime (221021112121009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510556060500 + 110510556060501.

It is an arithmetic number, because the mean of its divisors is an integer number (110510556060501).

Almost surely, 2^{221021112121001} is an apocalyptic number.

It is an amenable number.

221021112121001 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021112121001 is an equidigital number, since it uses as much as digits as its factorization.

221021112121001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 221021112121001 its reverse (100121211120122), we get a palindrome (321142323241123).

The spelling of 221021112121001 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred twelve million, one hundred twenty-one thousand, one".