1257806939 has 2 divisors, whose sum is σ = 1257806940. Its totient is φ = 1257806938.

The previous prime is 1257806923. The next prime is 1257806947. The reversal of 1257806939 is 9396087521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1257806939 - 2⁴ = 1257806923 is a prime.

It is not a weakly prime, because it can be changed into another prime (1257806909) 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, 628903469 + 628903470.

It is an arithmetic number, because the mean of its divisors is an integer number (628903470).

Almost surely, 2^1257806939 is an apocalyptic number.

1257806939 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257806939 is an equidigital number, since it uses as much as digits as its factorization.

1257806939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816480, while the sum is 50.

The square root of 1257806939 is about 35465.5739978927. The cubic root of 1257806939 is about 1079.4552977400.

The spelling of 1257806939 in words is "one billion, two hundred fifty-seven million, eight hundred six thousand, nine hundred thirty-nine".