256978 has 4 divisors (see below), whose sum is σ = 385470. Its totient is φ = 128488.

The previous prime is 256967. The next prime is 256981. The reversal of 256978 is 879652.

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

It can be written as a sum of positive squares in only one way, i.e., 253009 + 3969 = 503^2 + 63^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64243 + ... + 64246.

2²⁵⁶⁹⁷⁸ is an apocalyptic number.

256978 is a deficient number, since it is larger than the sum of its proper divisors (128492).

256978 is a wasteful number, since it uses less digits than its factorization.

256978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128491.

The product of its digits is 30240, while the sum is 37.

The square root of 256978 is about 506.9299754404. The cubic root of 256978 is about 63.5767975699.

The spelling of 256978 in words is "two hundred fifty-six thousand, nine hundred seventy-eight".