1031321021 has 2 divisors, whose sum is σ = 1031321022. Its totient is φ = 1031321020.

The previous prime is 1031320993. The next prime is 1031321023. The reversal of 1031321021 is 1201231301.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1028805625 + 2515396 = 32075^2 + 1586^2 .

It is a cyclic number.

It is not a de Polignac number, because 1031321021 - 2¹⁸ = 1031058877 is a prime.

Together with 1031321023, 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 = 1031320987 and 1031321005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1031321023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 515660510 + 515660511.

It is an arithmetic number, because the mean of its divisors is an integer number (515660511).

Almost surely, 2^1031321021 is an apocalyptic number.

It is an amenable number.

1031321021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1031321021 is an equidigital number, since it uses as much as digits as its factorization.

1031321021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1031321021 is about 32114.1872230950. The cubic root of 1031321021 is about 1010.3331975854. Note that the first 3 decimals are identical.

Adding to 1031321021 its reverse (1201231301), we get a palindrome (2232552322).

The spelling of 1031321021 in words is "one billion, thirty-one million, three hundred twenty-one thousand, twenty-one".