256398399 has 16 divisors (see below), whose sum is σ = 380147040. Its totient is φ = 170798400.

The previous prime is 256398397. The next prime is 256398413. The reversal of 256398399 is 993893652.

It is not a de Polignac number, because 256398399 - 2¹ = 256398397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256398391) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41299 + ... + 47099.

It is an arithmetic number, because the mean of its divisors is an integer number (23759190).

Almost surely, 2^256398399 is an apocalyptic number.

256398399 is a deficient number, since it is larger than the sum of its proper divisors (123748641).

256398399 is a wasteful number, since it uses less digits than its factorization.

256398399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7447 (or 7441 counting only the distinct ones).

The product of its digits is 3149280, while the sum is 54.

The square root of 256398399 is about 16012.4451287116. The cubic root of 256398399 is about 635.2896349584.

The spelling of 256398399 in words is "two hundred fifty-six million, three hundred ninety-eight thousand, three hundred ninety-nine".