1256266091 has 2 divisors, whose sum is σ = 1256266092. Its totient is φ = 1256266090.

The previous prime is 1256266021. The next prime is 1256266097. The reversal of 1256266091 is 1906626521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1256266091 - 2¹⁰ = 1256265067 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256266097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628133045 + 628133046.

It is an arithmetic number, because the mean of its divisors is an integer number (628133046).

Almost surely, 2^1256266091 is an apocalyptic number.

1256266091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256266091 is an equidigital number, since it uses as much as digits as its factorization.

1256266091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 1256266091 is about 35443.8441904938. The cubic root of 1256266091 is about 1079.0143301760.

The spelling of 1256266091 in words is "one billion, two hundred fifty-six million, two hundred sixty-six thousand, ninety-one".