1256009197 has 2 divisors, whose sum is σ = 1256009198. Its totient is φ = 1256009196.

The previous prime is 1256009191. The next prime is 1256009201. The reversal of 1256009197 is 7919006521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1140683076 + 115326121 = 33774^2 + 10739^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256009197 - 2³ = 1256009189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1256009191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628004598 + 628004599.

It is an arithmetic number, because the mean of its divisors is an integer number (628004599).

Almost surely, 2^1256009197 is an apocalyptic number.

It is an amenable number.

1256009197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256009197 is an equidigital number, since it uses as much as digits as its factorization.

1256009197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34020, while the sum is 40.

The square root of 1256009197 is about 35440.2200472853. The cubic root of 1256009197 is about 1078.9407759065.

The spelling of 1256009197 in words is "one billion, two hundred fifty-six million, nine thousand, one hundred ninety-seven".