1256368655 has 4 divisors (see below), whose sum is σ = 1507642392. Its totient is φ = 1005094920.

The previous prime is 1256368637. The next prime is 1256368661. The reversal of 1256368655 is 5568636521.

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

It is not a de Polignac number, because 1256368655 - 2¹⁴ = 1256352271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125636861 + ... + 125636870.

It is an arithmetic number, because the mean of its divisors is an integer number (376910598).

Almost surely, 2^1256368655 is an apocalyptic number.

1256368655 is a deficient number, since it is larger than the sum of its proper divisors (251273737).

1256368655 is an equidigital number, since it uses as much as digits as its factorization.

1256368655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251273736.

The product of its digits is 1296000, while the sum is 47.

The square root of 1256368655 is about 35445.2910130528. The cubic root of 1256368655 is about 1079.0436936511.

It can be divided in two parts, 12563 and 68655, that added together give a palindrome (81218).

The spelling of 1256368655 in words is "one billion, two hundred fifty-six million, three hundred sixty-eight thousand, six hundred fifty-five".