221121211001 has 2 divisors, whose sum is σ = 221121211002. Its totient is φ = 221121211000.

The previous prime is 221121210971. The next prime is 221121211019. The reversal of 221121211001 is 100112121122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153221359225 + 67899851776 = 391435^2 + 260576^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121211001 - 2²² = 221117016697 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (221121211081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560605500 + 110560605501.

It is an arithmetic number, because the mean of its divisors is an integer number (110560605501).

Almost surely, 2^221121211001 is an apocalyptic number.

It is an amenable number.

221121211001 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121211001 is an equidigital number, since it uses as much as digits as its factorization.

221121211001 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 14.

Adding to 221121211001 its reverse (100112121122), we get a palindrome (321233332123).

The spelling of 221121211001 in words is "two hundred twenty-one billion, one hundred twenty-one million, two hundred eleven thousand, one".