256398613 has 4 divisors (see below), whose sum is σ = 264669568. Its totient is φ = 248127660.

The previous prime is 256398589. The next prime is 256398619. The reversal of 256398613 is 316893652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256398613 - 2²¹ = 254301461 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256398613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256398619) 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, 4135431 + ... + 4135492.

It is an arithmetic number, because the mean of its divisors is an integer number (66167392).

Almost surely, 2^256398613 is an apocalyptic number.

It is an amenable number.

256398613 is a deficient number, since it is larger than the sum of its proper divisors (8270955).

256398613 is an equidigital number, since it uses as much as digits as its factorization.

256398613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8270954.

The product of its digits is 233280, while the sum is 43.

The square root of 256398613 is about 16012.4518110126. The cubic root of 256398613 is about 635.2898117041.

The spelling of 256398613 in words is "two hundred fifty-six million, three hundred ninety-eight thousand, six hundred thirteen".