1256987 has 8 divisors (see below), whose sum is σ = 1298256. Its totient is φ = 1216512.

The previous prime is 1256953. The next prime is 1256989. The reversal of 1256987 is 7896521.

1256987 is nontrivially palindromic in base 9.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1256987 - 2⁶ = 1256923 is a prime.

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

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1256987.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256989) 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 7 ways as a sum of consecutive naturals, for example, 4763 + ... + 5019.

It is an arithmetic number, because the mean of its divisors is an integer number (162282).

2^1256987 is an apocalyptic number.

1256987 is a deficient number, since it is larger than the sum of its proper divisors (41269).

1256987 is an equidigital number, since it uses as much as digits as its factorization.

1256987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397.

The product of its digits is 30240, while the sum is 38.

The square root of 1256987 is about 1121.1543158727. The cubic root of 1256987 is about 107.9220688367.

The spelling of 1256987 in words is "one million, two hundred fifty-six thousand, nine hundred eighty-seven".