1256836085 has 4 divisors (see below), whose sum is σ = 1508203308. Its totient is φ = 1005468864.

The previous prime is 1256836079. The next prime is 1256836103. The reversal of 1256836085 is 5806386521.

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

It can be written as a sum of positive squares in 2 ways, for example, as 178436164 + 1078399921 = 13358^2 + 32839^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256836085 - 2⁸ = 1256835829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 125683604 + ... + 125683613.

It is an arithmetic number, because the mean of its divisors is an integer number (377050827).

Almost surely, 2^1256836085 is an apocalyptic number.

It is an amenable number.

1256836085 is a deficient number, since it is larger than the sum of its proper divisors (251367223).

1256836085 is an equidigital number, since it uses as much as digits as its factorization.

1256836085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251367222.

The product of its (nonzero) digits is 345600, while the sum is 44.

The square root of 1256836085 is about 35451.8840825139. The cubic root of 1256836085 is about 1079.1774959003.

The spelling of 1256836085 in words is "one billion, two hundred fifty-six million, eight hundred thirty-six thousand, eighty-five".