1001021001989 has 2 divisors, whose sum is σ = 1001021001990. Its totient is φ = 1001021001988.

The previous prime is 1001021001973. The next prime is 1001021002013. The reversal of 1001021001989 is 9891001201001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 963505185889 + 37515816100 = 981583^2 + 193690^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001021001989 - 2⁴ = 1001021001973 is a prime.

It is a super-2 number, since 2×1001021001989² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001021001089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500510500994 + 500510500995.

It is an arithmetic number, because the mean of its divisors is an integer number (500510500995).

Almost surely, 2^{1001021001989} is an apocalyptic number.

It is an amenable number.

1001021001989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001021001989 is an equidigital number, since it uses as much as digits as its factorization.

1001021001989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 32.

The spelling of 1001021001989 in words is "one trillion, one billion, twenty-one million, one thousand, nine hundred eighty-nine".