1256387 has 4 divisors (see below), whose sum is σ = 1370616. Its totient is φ = 1142160.

The previous prime is 1256383. The next prime is 1256389. The reversal of 1256387 is 7836521.

It is a happy number.

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 1256387 - 2² = 1256383 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57098 + ... + 57119.

It is an arithmetic number, because the mean of its divisors is an integer number (342654).

2^1256387 is an apocalyptic number.

1256387 is a deficient number, since it is larger than the sum of its proper divisors (114229).

1256387 is a wasteful number, since it uses less digits than its factorization.

1256387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114228.

The product of its digits is 10080, while the sum is 32.

The square root of 1256387 is about 1120.8867025708. The cubic root of 1256387 is about 107.9048945549.

It can be divided in two parts, 12563 and 87, that multiplied together give a triangular number (1092981 = T₁₄₇₈).

The spelling of 1256387 in words is "one million, two hundred fifty-six thousand, three hundred eighty-seven".