1002020021993 has 4 divisors (see below), whose sum is σ = 1002027064020. Its totient is φ = 1002012979968.

The previous prime is 1002020021917. The next prime is 1002020022011. The reversal of 1002020021993 is 3991200202001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 105292462144 + 896727559849 = 324488^2 + 946957^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1002020021993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1002020023993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3303080 + ... + 3593657.

It is an arithmetic number, because the mean of its divisors is an integer number (250506766005).

Almost surely, 2^{1002020021993} is an apocalyptic number.

It is an amenable number.

1002020021993 is a deficient number, since it is larger than the sum of its proper divisors (7042027).

1002020021993 is an equidigital number, since it uses as much as digits as its factorization.

1002020021993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7042026.

The product of its (nonzero) digits is 1944, while the sum is 29.

Adding to 1002020021993 its reverse (3991200202001), we get a palindrome (4993220223994).

The spelling of 1002020021993 in words is "one trillion, two billion, twenty million, twenty-one thousand, nine hundred ninety-three".