1002102020021 has 4 divisors (see below), whose sum is σ = 1002242752044. Its totient is φ = 1001961288000.

The previous prime is 1002102020011. The next prime is 1002102020041. The reversal of 1002102020021 is 1200202012001.

It is a happy number.

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 273999902500 + 728102117521 = 523450^2 + 853289^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002102020021 - 2²² = 1002097825717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1002102019984 and 1002102020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002102020011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70355330 + ... + 70369571.

It is an arithmetic number, because the mean of its divisors is an integer number (250560688011).

Almost surely, 2^{1002102020021} is an apocalyptic number.

It is an amenable number.

1002102020021 is a deficient number, since it is larger than the sum of its proper divisors (140732023).

1002102020021 is an equidigital number, since it uses as much as digits as its factorization.

1002102020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140732022.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 1002102020021 its reverse (1200202012001), we get a palindrome (2202304032022).

The spelling of 1002102020021 in words is "one trillion, two billion, one hundred two million, twenty thousand, twenty-one".