1001211101221 has 2 divisors, whose sum is σ = 1001211101222. Its totient is φ = 1001211101220.

The previous prime is 1001211101183. The next prime is 1001211101321. The reversal of 1001211101221 is 1221011121001.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 580665336196 + 420545765025 = 762014^2 + 648495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1001211101221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001211101321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500605550610 + 500605550611.

It is an arithmetic number, because the mean of its divisors is an integer number (500605550611).

Almost surely, 2^{1001211101221} is an apocalyptic number.

It is an amenable number.

1001211101221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001211101221 is an equidigital number, since it uses as much as digits as its factorization.

1001211101221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1001211101221 its reverse (1221011121001), we get a palindrome (2222222222222).

The spelling of 1001211101221 in words is "one trillion, one billion, two hundred eleven million, one hundred one thousand, two hundred twenty-one".