1318189987 has 2 divisors, whose sum is σ = 1318189988. Its totient is φ = 1318189986.

The previous prime is 1318189969. The next prime is 1318190011. The reversal of 1318189987 is 7899818131.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1318189987 is a prime.

It is not a weakly prime, because it can be changed into another prime (1318189937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 659094993 + 659094994.

It is an arithmetic number, because the mean of its divisors is an integer number (659094994).

Almost surely, 2^1318189987 is an apocalyptic number.

1318189987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1318189987 is an equidigital number, since it uses as much as digits as its factorization.

1318189987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 55.

The square root of 1318189987 is about 36306.8862201098. The cubic root of 1318189987 is about 1096.4596886554.

The spelling of 1318189987 in words is "one billion, three hundred eighteen million, one hundred eighty-nine thousand, nine hundred eighty-seven".