1318172549 has 2 divisors, whose sum is σ = 1318172550. Its totient is φ = 1318172548.

The previous prime is 1318172521. The next prime is 1318172579. The reversal of 1318172549 is 9452718131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1022848324 + 295324225 = 31982^2 + 17185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1318172549 - 2²⁸ = 1049737093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1318172579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 659086274 + 659086275.

It is an arithmetic number, because the mean of its divisors is an integer number (659086275).

Almost surely, 2^1318172549 is an apocalyptic number.

It is an amenable number.

1318172549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1318172549 is an equidigital number, since it uses as much as digits as its factorization.

1318172549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 41.

The square root of 1318172549 is about 36306.6460720348. The cubic root of 1318172549 is about 1096.4548537053.

The spelling of 1318172549 in words is "one billion, three hundred eighteen million, one hundred seventy-two thousand, five hundred forty-nine".