256399903 has 4 divisors (see below), whose sum is σ = 256816080. Its totient is φ = 255983728.

The previous prime is 256399901. The next prime is 256399939. The reversal of 256399903 is 309993652.

It is a happy number.

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 256399903 - 2¹ = 256399901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256399901) 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, 207163 + ... + 208396.

It is an arithmetic number, because the mean of its divisors is an integer number (64204020).

Almost surely, 2^256399903 is an apocalyptic number.

256399903 is a deficient number, since it is larger than the sum of its proper divisors (416177).

256399903 is an equidigital number, since it uses as much as digits as its factorization.

256399903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416176.

The product of its (nonzero) digits is 393660, while the sum is 46.

The square root of 256399903 is about 16012.4920921136. The cubic root of 256399903 is about 635.2908771317.

The spelling of 256399903 in words is "two hundred fifty-six million, three hundred ninety-nine thousand, nine hundred three".