1286257949 has 2 divisors, whose sum is σ = 1286257950. Its totient is φ = 1286257948.

The previous prime is 1286257897. The next prime is 1286257969. The reversal of 1286257949 is 9497526821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 764135449 + 522122500 = 27643^2 + 22850^2 .

It is a cyclic number.

It is not a de Polignac number, because 1286257949 - 2²⁴ = 1269480733 is a prime.

It is a super-2 number, since 2×1286257949² = 3308919022731373202, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1286257949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1286257969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643128974 + 643128975.

It is an arithmetic number, because the mean of its divisors is an integer number (643128975).

Almost surely, 2^1286257949 is an apocalyptic number.

It is an amenable number.

1286257949 is a deficient number, since it is larger than the sum of its proper divisors (1).

1286257949 is an equidigital number, since it uses as much as digits as its factorization.

1286257949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2177280, while the sum is 53.

The square root of 1286257949 is about 35864.4385011114. The cubic root of 1286257949 is about 1087.5336173868.

The spelling of 1286257949 in words is "one billion, two hundred eighty-six million, two hundred fifty-seven thousand, nine hundred forty-nine".