1011211221001 has 2 divisors, whose sum is σ = 1011211221002. Its totient is φ = 1011211221000.

The previous prime is 1011211220993. The next prime is 1011211221019. The reversal of 1011211221001 is 1001221121101.

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., 1007373542400 + 3837678601 = 1003680^2 + 61949^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011211221001 - 2³ = 1011211220993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1011211221701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505605610500 + 505605610501.

It is an arithmetic number, because the mean of its divisors is an integer number (505605610501).

Almost surely, 2^{1011211221001} is an apocalyptic number.

It is an amenable number.

1011211221001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011211221001 is an equidigital number, since it uses as much as digits as its factorization.

1011211221001 is an odious number, because the sum of its binary digits is odd.

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

Adding to 1011211221001 its reverse (1001221121101), we get a palindrome (2012432342102).

The spelling of 1011211221001 in words is "one trillion, eleven billion, two hundred eleven million, two hundred twenty-one thousand, one".