1256256311 has 4 divisors (see below), whose sum is σ = 1256701032. Its totient is φ = 1255811592.

The previous prime is 1256256263. The next prime is 1256256317. The reversal of 1256256311 is 1136526521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1256256311 - 2⁶ = 1256256247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256256317) 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 in 3 ways as a sum of consecutive naturals, for example, 218096 + ... + 223781.

It is an arithmetic number, because the mean of its divisors is an integer number (314175258).

Almost surely, 2^1256256311 is an apocalyptic number.

1256256311 is a deficient number, since it is larger than the sum of its proper divisors (444721).

1256256311 is an equidigital number, since it uses as much as digits as its factorization.

1256256311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444720.

The product of its digits is 10800, while the sum is 32.

The square root of 1256256311 is about 35443.7062255064. The cubic root of 1256256311 is about 1079.0115301356.

The spelling of 1256256311 in words is "one billion, two hundred fifty-six million, two hundred fifty-six thousand, three hundred eleven".