256988783 has 4 divisors (see below), whose sum is σ = 257059368. Its totient is φ = 256918200.

The previous prime is 256988777. The next prime is 256988789. The reversal of 256988783 is 387889652.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (256988777) and next prime (256988789).

It is a cyclic number.

It is not a de Polignac number, because 256988783 - 2¹² = 256984687 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 (256988789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29516 + ... + 37217.

It is an arithmetic number, because the mean of its divisors is an integer number (64264842).

Almost surely, 2^256988783 is an apocalyptic number.

256988783 is a deficient number, since it is larger than the sum of its proper divisors (70585).

256988783 is an equidigital number, since it uses as much as digits as its factorization.

256988783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70584.

The product of its digits is 5806080, while the sum is 56.

The square root of 256988783 is about 16030.8696894460. The cubic root of 256988783 is about 635.7768680167.

The spelling of 256988783 in words is "two hundred fifty-six million, nine hundred eighty-eight thousand, seven hundred eighty-three".