256782778 has 8 divisors (see below), whose sum is σ = 440199072. Its totient is φ = 110049756.

The previous prime is 256782769. The next prime is 256782781. The reversal of 256782778 is 877287652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9170800 + ... + 9170827.

It is an arithmetic number, because the mean of its divisors is an integer number (55024884).

Almost surely, 2^256782778 is an apocalyptic number.

256782778 is a deficient number, since it is larger than the sum of its proper divisors (183416294).

256782778 is a wasteful number, since it uses less digits than its factorization.

256782778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18341636.

The product of its digits is 2634240, while the sum is 52.

The square root of 256782778 is about 16024.4431416508. The cubic root of 256782778 is about 635.6069407222.

The spelling of 256782778 in words is "two hundred fifty-six million, seven hundred eighty-two thousand, seven hundred seventy-eight".