1001100001021 has 2 divisors, whose sum is σ = 1001100001022. Its totient is φ = 1001100001020.

The previous prime is 1001100001019. The next prime is 1001100001049. The reversal of 1001100001021 is 1201000011001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 534235275396 + 466864725625 = 730914^2 + 683275^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001100001021 - 2¹ = 1001100001019 is a prime.

Together with 1001100001019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1001100000995 and 1001100001013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001100001721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500550000510 + 500550000511.

It is an arithmetic number, because the mean of its divisors is an integer number (500550000511).

Almost surely, 2^{1001100001021} is an apocalyptic number.

It is an amenable number.

1001100001021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001100001021 is an equidigital number, since it uses as much as digits as its factorization.

1001100001021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 1001100001021 its reverse (1201000011001), we get a palindrome (2202100012022).

The spelling of 1001100001021 in words is "one trillion, one billion, one hundred million, one thousand, twenty-one".