1326013721 has 2 divisors, whose sum is σ = 1326013722. Its totient is φ = 1326013720.

The previous prime is 1326013709. The next prime is 1326013751. The reversal of 1326013721 is 1273106231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 901200400 + 424813321 = 30020^2 + 20611^2 .

It is a cyclic number.

It is not a de Polignac number, because 1326013721 - 2¹⁸ = 1325751577 is a prime.

It is not a weakly prime, because it can be changed into another prime (1326013751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663006860 + 663006861.

It is an arithmetic number, because the mean of its divisors is an integer number (663006861).

Almost surely, 2^1326013721 is an apocalyptic number.

It is an amenable number.

1326013721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1326013721 is an equidigital number, since it uses as much as digits as its factorization.

1326013721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 1326013721 is about 36414.4713129272. The cubic root of 1326013721 is about 1098.6246505144.

Adding to 1326013721 its reverse (1273106231), we get a palindrome (2599119952).

The spelling of 1326013721 in words is "one billion, three hundred twenty-six million, thirteen thousand, seven hundred twenty-one".