1257042209 has 2 divisors, whose sum is σ = 1257042210. Its totient is φ = 1257042208.

The previous prime is 1257042167. The next prime is 1257042211. The reversal of 1257042209 is 9022407521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 869070400 + 387971809 = 29480^2 + 19697^2 .

It is a cyclic number.

It is not a de Polignac number, because 1257042209 - 2²⁰ = 1255993633 is a prime.

Together with 1257042211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1257042289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628521104 + 628521105.

It is an arithmetic number, because the mean of its divisors is an integer number (628521105).

Almost surely, 2^1257042209 is an apocalyptic number.

It is an amenable number.

1257042209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257042209 is an equidigital number, since it uses as much as digits as its factorization.

1257042209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 1257042209 is about 35454.7910584733. The cubic root of 1257042209 is about 1079.2364885368.

The spelling of 1257042209 in words is "one billion, two hundred fifty-seven million, forty-two thousand, two hundred nine".