1321131913 has 2 divisors, whose sum is σ = 1321131914. Its totient is φ = 1321131912.

The previous prime is 1321131857. The next prime is 1321131923. The reversal of 1321131913 is 3191311231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1242774009 + 78357904 = 35253^2 + 8852^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321131913 - 2¹⁷ = 1321000841 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321131923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660565956 + 660565957.

It is an arithmetic number, because the mean of its divisors is an integer number (660565957).

Almost surely, 2^1321131913 is an apocalyptic number.

It is an amenable number.

1321131913 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321131913 is an equidigital number, since it uses as much as digits as its factorization.

1321131913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 486, while the sum is 25.

The square root of 1321131913 is about 36347.3783511273. The cubic root of 1321131913 is about 1097.2747726137.

The spelling of 1321131913 in words is "one billion, three hundred twenty-one million, one hundred thirty-one thousand, nine hundred thirteen".