1002131021 has 4 divisors (see below), whose sum is σ = 1003666332. Its totient is φ = 1000595712.

The previous prime is 1002130949. The next prime is 1002131089. The reversal of 1002131021 is 1201312001.

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 597558025 + 404572996 = 24445^2 + 20114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002131021 - 2¹⁸ = 1001868877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1002130993 and 1002131011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002131621) 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, 766676 + ... + 767981.

It is an arithmetic number, because the mean of its divisors is an integer number (250916583).

Almost surely, 2^1002131021 is an apocalyptic number.

It is an amenable number.

1002131021 is a deficient number, since it is larger than the sum of its proper divisors (1535311).

1002131021 is an equidigital number, since it uses as much as digits as its factorization.

1002131021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535310.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 1002131021 is about 31656.4530704247. The cubic root of 1002131021 is about 1000.7098363465.

Adding to 1002131021 its reverse (1201312001), we get a palindrome (2203443022).

The spelling of 1002131021 in words is "one billion, two million, one hundred thirty-one thousand, twenty-one".