256940019 has 20 divisors (see below), whose sum is σ = 438656944. Its totient is φ = 146822544.

The previous prime is 256940017. The next prime is 256940027. The reversal of 256940019 is 910049652.

It is not a de Polignac number, because 256940019 - 2¹ = 256940017 is a prime.

It is a super-2 number, since 2×256940019² = 132036346727440722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256940017) 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 19 ways as a sum of consecutive naturals, for example, 226012 + ... + 227145.

Almost surely, 2^256940019 is an apocalyptic number.

256940019 is a deficient number, since it is larger than the sum of its proper divisors (181716925).

256940019 is an equidigital number, since it uses as much as digits as its factorization.

256940019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453176 (or 453167 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 256940019 is about 16029.3486767242. The cubic root of 256940019 is about 635.7366522739.

The spelling of 256940019 in words is "two hundred fifty-six million, nine hundred forty thousand, nineteen".