20111021221001 has 2 divisors, whose sum is σ = 20111021221002. Its totient is φ = 20111021221000.

The previous prime is 20111021220949. The next prime is 20111021221009. The reversal of 20111021221001 is 10012212011102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18940948494400 + 1170072726601 = 4352120^2 + 1081699^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111021221001 - 2⁶ = 20111021220937 is a prime.

It is not a weakly prime, because it can be changed into another prime (20111021221009) 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, 10055510610500 + 10055510610501.

It is an arithmetic number, because the mean of its divisors is an integer number (10055510610501).

Almost surely, 2^{20111021221001} is an apocalyptic number.

It is an amenable number.

20111021221001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111021221001 is an equidigital number, since it uses as much as digits as its factorization.

20111021221001 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 20111021221001 its reverse (10012212011102), we get a palindrome (30123233232103).

The spelling of 20111021221001 in words is "twenty trillion, one hundred eleven billion, twenty-one million, two hundred twenty-one thousand, one".