1021001321 has 2 divisors, whose sum is σ = 1021001322. Its totient is φ = 1021001320.

The previous prime is 1021001299. The next prime is 1021001323. The reversal of 1021001321 is 1231001201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634485721 + 386515600 = 25189^2 + 19660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021001321 is a prime.

Together with 1021001323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1021001323) 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 as a sum of consecutive naturals, namely, 510500660 + 510500661.

It is an arithmetic number, because the mean of its divisors is an integer number (510500661).

Almost surely, 2^1021001321 is an apocalyptic number.

It is an amenable number.

1021001321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021001321 is an equidigital number, since it uses as much as digits as its factorization.

1021001321 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1021001321 is about 31953.1112882611. Note that the first 3 decimals coincide. The cubic root of 1021001321 is about 1006.9519980590.

Adding to 1021001321 its reverse (1231001201), we get a palindrome (2252002522).

The spelling of 1021001321 in words is "one billion, twenty-one million, one thousand, three hundred twenty-one".