1256377855 has 4 divisors (see below), whose sum is σ = 1507653432. Its totient is φ = 1005102280.

The previous prime is 1256377841. The next prime is 1256377861. The reversal of 1256377855 is 5587736521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5587736521 = 44549 ⋅125429.

It is not a de Polignac number, because 1256377855 - 2⁵ = 1256377823 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1256377799 and 1256377808.

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, 125637781 + ... + 125637790.

It is an arithmetic number, because the mean of its divisors is an integer number (376913358).

Almost surely, 2^1256377855 is an apocalyptic number.

1256377855 is a deficient number, since it is larger than the sum of its proper divisors (251275577).

1256377855 is an equidigital number, since it uses as much as digits as its factorization.

1256377855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251275576.

The product of its digits is 1764000, while the sum is 49.

The square root of 1256377855 is about 35445.4207902798. The cubic root of 1256377855 is about 1079.0463274793.

The spelling of 1256377855 in words is "one billion, two hundred fifty-six million, three hundred seventy-seven thousand, eight hundred fifty-five".