1605131317 has 2 divisors, whose sum is σ = 1605131318. Its totient is φ = 1605131316.

The previous prime is 1605131249. The next prime is 1605131323. The reversal of 1605131317 is 7131315061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1202286276 + 402845041 = 34674^2 + 20071^2 .

It is a cyclic number.

It is not a de Polignac number, because 1605131317 - 2²⁷ = 1470913589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1605131327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802565658 + 802565659.

It is an arithmetic number, because the mean of its divisors is an integer number (802565659).

Almost surely, 2^1605131317 is an apocalyptic number.

It is an amenable number.

1605131317 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605131317 is an equidigital number, since it uses as much as digits as its factorization.

1605131317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 1605131317 is about 40064.0901182093. The cubic root of 1605131317 is about 1170.8560995133.

Adding to 1605131317 its reverse (7131315061), we get a palindrome (8736446378).

The spelling of 1605131317 in words is "one billion, six hundred five million, one hundred thirty-one thousand, three hundred seventeen".