20021101111001 has 2 divisors, whose sum is σ = 20021101111002. Its totient is φ = 20021101111000.

The previous prime is 20021101110991. The next prime is 20021101111019. The reversal of 20021101111001 is 10011110112002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18962332139776 + 1058768971225 = 4354576^2 + 1028965^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021101111001 is a prime.

It is not a weakly prime, because it can be changed into another prime (20021101111201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010550555500 + 10010550555501.

It is an arithmetic number, because the mean of its divisors is an integer number (10010550555501).

Almost surely, 2^{20021101111001} is an apocalyptic number.

It is an amenable number.

20021101111001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021101111001 is an equidigital number, since it uses as much as digits as its factorization.

20021101111001 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20021101111001 its reverse (10011110112002), we get a palindrome (30032211223003).

The spelling of 20021101111001 in words is "twenty trillion, twenty-one billion, one hundred one million, one hundred eleven thousand, one".