1287671849 has 2 divisors, whose sum is σ = 1287671850. Its totient is φ = 1287671848.

The previous prime is 1287671843. The next prime is 1287671867. The reversal of 1287671849 is 9481767821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 816130624 + 471541225 = 28568^2 + 21715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1287671849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1287671849.

It is not a weakly prime, because it can be changed into another prime (1287671843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643835924 + 643835925.

It is an arithmetic number, because the mean of its divisors is an integer number (643835925).

Almost surely, 2^1287671849 is an apocalyptic number.

It is an amenable number.

1287671849 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287671849 is an equidigital number, since it uses as much as digits as its factorization.

1287671849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1354752, while the sum is 53.

The square root of 1287671849 is about 35884.1448135524. The cubic root of 1287671849 is about 1087.9319565402.

The spelling of 1287671849 in words is "one billion, two hundred eighty-seven million, six hundred seventy-one thousand, eight hundred forty-nine".