256015 has 4 divisors (see below), whose sum is σ = 307224. Its totient is φ = 204808.

The previous prime is 255989. The next prime is 256019. The reversal of 256015 is 510652.

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 256015 - 2⁷ = 255887 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 255983 and 256001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256019) 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, 25597 + ... + 25606.

It is an arithmetic number, because the mean of its divisors is an integer number (76806).

2²⁵⁶⁰¹⁵ is an apocalyptic number.

256015 is a deficient number, since it is larger than the sum of its proper divisors (51209).

256015 is an equidigital number, since it uses as much as digits as its factorization.

256015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51208.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 256015 is about 505.9792485863. The cubic root of 256015 is about 63.4972822116.

Adding to 256015 its reverse (510652), we get a palindrome (766667).

The spelling of 256015 in words is "two hundred fifty-six thousand, fifteen".