256531003 has 4 divisors (see below), whose sum is σ = 271621080. Its totient is φ = 241440928.

The previous prime is 256531001. The next prime is 256531021. The reversal of 256531003 is 300135652.

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 256531003 - 2¹ = 256531001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256531001) 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, 7545013 + ... + 7545046.

It is an arithmetic number, because the mean of its divisors is an integer number (67905270).

Almost surely, 2^256531003 is an apocalyptic number.

256531003 is a deficient number, since it is larger than the sum of its proper divisors (15090077).

256531003 is a wasteful number, since it uses less digits than its factorization.

256531003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15090076.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 256531003 is about 16016.5852477986. The cubic root of 256531003 is about 635.3991356788.

Adding to 256531003 its reverse (300135652), we get a palindrome (556666655).

The spelling of 256531003 in words is "two hundred fifty-six million, five hundred thirty-one thousand, three".