1111221001001 has 2 divisors, whose sum is σ = 1111221001002. Its totient is φ = 1111221001000.

The previous prime is 1111221000917. The next prime is 1111221001003. The reversal of 1111221001001 is 1001001221111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 585414735376 + 525806265625 = 765124^2 + 725125^2 .

It is a cyclic number.

It is not a de Polignac number, because 1111221001001 - 2¹⁴ = 1111220984617 is a prime.

It is a super-2 number, since 2×1111221001001² (a number of 25 digits) contains 22 as substring.

Together with 1111221001003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1111221001003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555610500500 + 555610500501.

It is an arithmetic number, because the mean of its divisors is an integer number (555610500501).

Almost surely, 2^{1111221001001} is an apocalyptic number.

It is an amenable number.

1111221001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111221001001 is an equidigital number, since it uses as much as digits as its factorization.

1111221001001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1111221001001 its reverse (1001001221111), we get a palindrome (2112222222112).

The spelling of 1111221001001 in words is "one trillion, one hundred eleven billion, two hundred twenty-one million, one thousand, one".