1256645 has 8 divisors (see below), whose sum is σ = 1624056. Its totient is φ = 927936.

The previous prime is 1256621. The next prime is 1256659. The reversal of 1256645 is 5466521.

It can be written as a sum of positive squares in 4 ways, for example, as 187489 + 1069156 = 433^2 + 1034^2 .

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 1256645 - 2⁸ = 1256389 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 7 ways as a sum of consecutive naturals, for example, 9602 + ... + 9731.

It is an arithmetic number, because the mean of its divisors is an integer number (203007).

2^1256645 is an apocalyptic number.

It is an amenable number.

1256645 is a deficient number, since it is larger than the sum of its proper divisors (367411).

1256645 is a wasteful number, since it uses less digits than its factorization.

1256645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19351.

The product of its digits is 7200, while the sum is 29.

The square root of 1256645 is about 1121.0017841199. The cubic root of 1256645 is about 107.9122801660.

The spelling of 1256645 in words is "one million, two hundred fifty-six thousand, six hundred forty-five".