1801202021081 has 2 divisors, whose sum is σ = 1801202021082. Its totient is φ = 1801202021080.

The previous prime is 1801202021063. The next prime is 1801202021107.

1801202021081 is nontrivially palindromic in base 10.

It is an a-pointer prime, because the next prime (1801202021107) can be obtained adding 1801202021081 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 922398893056 + 878803128025 = 960416^2 + 937445^2 .

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1801202021081 is a prime.

It is a super-2 number, since 2×1801202021081² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1801202021081.

It is not a weakly prime, because it can be changed into another prime (1801202021881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900601010540 + 900601010541.

It is an arithmetic number, because the mean of its divisors is an integer number (900601010541).

Almost surely, 2^{1801202021081} is an apocalyptic number.

It is an amenable number.

1801202021081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1801202021081 is an equidigital number, since it uses as much as digits as its factorization.

1801202021081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 26.

The spelling of 1801202021081 in words is "one trillion, eight hundred one billion, two hundred two million, twenty-one thousand, eighty-one".