1256457 has 4 divisors (see below), whose sum is σ = 1675280. Its totient is φ = 837636.

The previous prime is 1256449. The next prime is 1256477. The reversal of 1256457 is 7546521.

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.

It is not a de Polignac number, because 1256457 - 2³ = 1256449 is a prime.

It is a D-number.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 209407 + ... + 209412.

It is an arithmetic number, because the mean of its divisors is an integer number (418820).

2^1256457 is an apocalyptic number.

It is an amenable number.

1256457 is a deficient number, since it is larger than the sum of its proper divisors (418823).

1256457 is an equidigital number, since it uses as much as digits as its factorization.

1256457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418822.

The product of its digits is 8400, while the sum is 30.

The square root of 1256457 is about 1120.9179274148. The cubic root of 1256457 is about 107.9068985028.

Subtracting 1256457 from its reverse (7546521), we obtain a square (6290064 = 2508²).

It can be divided in two parts, 12564 and 57, that added together give a palindrome (12621).

The spelling of 1256457 in words is "one million, two hundred fifty-six thousand, four hundred fifty-seven".