256978519 has 4 divisors (see below), whose sum is σ = 293689744. Its totient is φ = 220267296.

The previous prime is 256978507. The next prime is 256978523. The reversal of 256978519 is 915879652.

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 256978519 - 2⁷ = 256978391 is a prime.

It is a super-2 number, since 2×256978519² = 132075918454866722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256978549) 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, 18355602 + ... + 18355615.

It is an arithmetic number, because the mean of its divisors is an integer number (73422436).

Almost surely, 2^256978519 is an apocalyptic number.

256978519 is a deficient number, since it is larger than the sum of its proper divisors (36711225).

256978519 is an equidigital number, since it uses as much as digits as its factorization.

256978519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36711224.

The product of its digits is 1360800, while the sum is 52.

The square root of 256978519 is about 16030.5495538986. The cubic root of 256978519 is about 635.7684037035.

The spelling of 256978519 in words is "two hundred fifty-six million, nine hundred seventy-eight thousand, five hundred nineteen".