1256985 has 16 divisors (see below), whose sum is σ = 2234880. Its totient is φ = 670320.

The previous prime is 1256953. The next prime is 1256989. The reversal of 1256985 is 5896521.

It is a happy number.

1256985 is a `hidden beast` number, since 12 + 569 + 85 = 666.

It is not a de Polignac number, because 1256985 - 2⁵ = 1256953 is a prime.

It is a super-2 number, since 2×1256985² = 3160022580450, which contains 22 as substring.

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

1256985 is a lucky number.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4521 + ... + 4790.

It is an arithmetic number, because the mean of its divisors is an integer number (139680).

2^1256985 is an apocalyptic number.

1256985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1256985 is a deficient number, since it is larger than the sum of its proper divisors (977895).

1256985 is an equidigital number, since it uses as much as digits as its factorization.

1256985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9325 (or 9319 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 1256985 is about 1121.1534239345. The cubic root of 1256985 is about 107.9220115982.

The spelling of 1256985 in words is "one million, two hundred fifty-six thousand, nine hundred eighty-five".