256486403 has 4 divisors (see below), whose sum is σ = 257399448. Its totient is φ = 255573360.

The previous prime is 256486387. The next prime is 256486421. The reversal of 256486403 is 304684652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256486403 - 2⁴ = 256486387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256486903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 456101 + ... + 456662.

It is an arithmetic number, because the mean of its divisors is an integer number (64349862).

Almost surely, 2^256486403 is an apocalyptic number.

256486403 is a deficient number, since it is larger than the sum of its proper divisors (913045).

256486403 is an equidigital number, since it uses as much as digits as its factorization.

256486403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913044.

The product of its (nonzero) digits is 138240, while the sum is 38.

The square root of 256486403 is about 16015.1928805119. The cubic root of 256486403 is about 635.3623104431.

The spelling of 256486403 in words is "two hundred fifty-six million, four hundred eighty-six thousand, four hundred three".