256135615 has 4 divisors (see below), whose sum is σ = 307362744. Its totient is φ = 204908488.

The previous prime is 256135603. The next prime is 256135639. The reversal of 256135615 is 516531652.

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 256135615 - 2¹⁹ = 255611327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25613557 + ... + 25613566.

It is an arithmetic number, because the mean of its divisors is an integer number (76840686).

Almost surely, 2^256135615 is an apocalyptic number.

256135615 is a deficient number, since it is larger than the sum of its proper divisors (51227129).

256135615 is an equidigital number, since it uses as much as digits as its factorization.

256135615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51227128.

The product of its digits is 27000, while the sum is 34.

The square root of 256135615 is about 16004.2374076368. The cubic root of 256135615 is about 635.0725235951.

The spelling of 256135615 in words is "two hundred fifty-six million, one hundred thirty-five thousand, six hundred fifteen".