1002320021 has 2 divisors, whose sum is σ = 1002320022. Its totient is φ = 1002320020.

The previous prime is 1002319999. The next prime is 1002320023. The reversal of 1002320021 is 1200232001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 814246225 + 188073796 = 28535^2 + 13714^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002320021 - 2²² = 998125717 is a prime.

Together with 1002320023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1002319984 and 1002320011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1002320023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501160010 + 501160011.

It is an arithmetic number, because the mean of its divisors is an integer number (501160011).

Almost surely, 2^1002320021 is an apocalyptic number.

It is an amenable number.

1002320021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002320021 is an equidigital number, since it uses as much as digits as its factorization.

1002320021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 1002320021 is about 31659.4381030365. The cubic root of 1002320021 is about 1000.7727430477.

Adding to 1002320021 its reverse (1200232001), we get a palindrome (2202552022).

The spelling of 1002320021 in words is "one billion, two million, three hundred twenty thousand, twenty-one".