1256401 has 4 divisors (see below), whose sum is σ = 1263600. Its totient is φ = 1249204.

The previous prime is 1256393. The next prime is 1256407. The reversal of 1256401 is 1046521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1046521 = 7 ⋅149503.

It is a cyclic number.

It is not a de Polignac number, because 1256401 - 2³ = 1256393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256407) 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, 3331 + ... + 3688.

It is an arithmetic number, because the mean of its divisors is an integer number (315900).

2^1256401 is an apocalyptic number.

It is an amenable number.

1256401 is a deficient number, since it is larger than the sum of its proper divisors (7199).

1256401 is an equidigital number, since it uses as much as digits as its factorization.

1256401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7198.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1256401 is about 1120.8929476092. The cubic root of 1256401 is about 107.9052953504.

Adding to 1256401 its product of nonzero digits (240), we get a square (1256641 = 1121²).

The spelling of 1256401 in words is "one million, two hundred fifty-six thousand, four hundred one".