11001020021 has 2 divisors, whose sum is σ = 11001020022. Its totient is φ = 11001020020.

The previous prime is 11001019999. The next prime is 11001020027. The reversal of 11001020021 is 12002010011.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6730397521 + 4270622500 = 82039^2 + 65350^2 .

It is a cyclic number.

It is not a de Polignac number, because 11001020021 - 2¹⁰ = 11001018997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11001019990 and 11001020008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11001020027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5500510010 + 5500510011.

It is an arithmetic number, because the mean of its divisors is an integer number (5500510011).

Almost surely, 2^11001020021 is an apocalyptic number.

It is an amenable number.

11001020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11001020021 is an equidigital number, since it uses as much as digits as its factorization.

11001020021 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 8.

Adding to 11001020021 its reverse (12002010011), we get a palindrome (23003030032).

It can be divided in two parts, 110010 and 20021, that added together give a palindrome (130031).

The spelling of 11001020021 in words is "eleven billion, one million, twenty thousand, twenty-one".