256317936487 has 4 divisors (see below), whose sum is σ = 256559519016. Its totient is φ = 256076353960.

The previous prime is 256317936473. The next prime is 256317936517. The reversal of 256317936487 is 784639713652.

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 256317936487 - 2³¹ = 254170452839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256317931487) 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, 120789673 + ... + 120791794.

It is an arithmetic number, because the mean of its divisors is an integer number (64139879754).

Almost surely, 2^256317936487 is an apocalyptic number.

256317936487 is a deficient number, since it is larger than the sum of its proper divisors (241582529).

256317936487 is a wasteful number, since it uses less digits than its factorization.

256317936487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241582528.

The product of its digits is 45722880, while the sum is 61.

The spelling of 256317936487 in words is "two hundred fifty-six billion, three hundred seventeen million, nine hundred thirty-six thousand, four hundred eighty-seven".