1310021021 has 2 divisors, whose sum is σ = 1310021022. Its totient is φ = 1310021020.

The previous prime is 1310021017. The next prime is 1310021029. The reversal of 1310021021 is 1201200131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 893412100 + 416608921 = 29890^2 + 20411^2 .

It is a cyclic number.

It is not a de Polignac number, because 1310021021 - 2² = 1310021017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1310020993 and 1310021011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1310021029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655010510 + 655010511.

It is an arithmetic number, because the mean of its divisors is an integer number (655010511).

Almost surely, 2^1310021021 is an apocalyptic number.

It is an amenable number.

1310021021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1310021021 is an equidigital number, since it uses as much as digits as its factorization.

1310021021 is an evil number, because the sum of its binary digits is even.

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

The square root of 1310021021 is about 36194.2125346028. The cubic root of 1310021021 is about 1094.1900339647.

Adding to 1310021021 its reverse (1201200131), we get a palindrome (2511221152).

The spelling of 1310021021 in words is "one billion, three hundred ten million, twenty-one thousand, twenty-one".