131321321 has 2 divisors, whose sum is σ = 131321322. Its totient is φ = 131321320.

The previous prime is 131321317. The next prime is 131321327. The reversal of 131321321 is 123123131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90935296 + 40386025 = 9536^2 + 6355^2 .

It is a cyclic number.

It is not a de Polignac number, because 131321321 - 2² = 131321317 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131321321.

It is not a weakly prime, because it can be changed into another prime (131321327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65660660 + 65660661.

It is an arithmetic number, because the mean of its divisors is an integer number (65660661).

Almost surely, 2^131321321 is an apocalyptic number.

It is an amenable number.

131321321 is a deficient number, since it is larger than the sum of its proper divisors (1).

131321321 is an equidigital number, since it uses as much as digits as its factorization.

131321321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108, while the sum is 17.

The square root of 131321321 is about 11459.5515182750. The cubic root of 131321321 is about 508.2902130463.

Adding to 131321321 its reverse (123123131), we get a palindrome (254444452).

The spelling of 131321321 in words is "one hundred thirty-one million, three hundred twenty-one thousand, three hundred twenty-one".