221021221000121 has 2 divisors, whose sum is σ = 221021221000122. Its totient is φ = 221021221000120.

The previous prime is 221021221000103. The next prime is 221021221000141. The reversal of 221021221000121 is 121000122120122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 218324856672400 + 2696364327721 = 14775820^2 + 1642061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221021221000121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221021221000121.

It is not a weakly prime, because it can be changed into another prime (221021221000141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510610500060 + 110510610500061.

It is an arithmetic number, because the mean of its divisors is an integer number (110510610500061).

Almost surely, 2^{221021221000121} is an apocalyptic number.

It is an amenable number.

221021221000121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021221000121 is an equidigital number, since it uses as much as digits as its factorization.

221021221000121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221021221000121 its reverse (121000122120122), we get a palindrome (342021343120243).

The spelling of 221021221000121 in words is "two hundred twenty-one trillion, twenty-one billion, two hundred twenty-one million, one hundred twenty-one", and thus it is an aban number.