256820818 has 8 divisors (see below), whose sum is σ = 388971648. Its totient is φ = 127163604.

The previous prime is 256820813. The next prime is 256820821. The reversal of 256820818 is 818028652.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (256820813) 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, 623146 + ... + 623557.

It is an arithmetic number, because the mean of its divisors is an integer number (48621456).

Almost surely, 2^256820818 is an apocalyptic number.

256820818 is a deficient number, since it is larger than the sum of its proper divisors (132150830).

256820818 is a wasteful number, since it uses less digits than its factorization.

256820818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1246808.

The product of its (nonzero) digits is 61440, while the sum is 40.

The square root of 256820818 is about 16025.6300344167. The cubic root of 256820818 is about 635.6383256076.

The spelling of 256820818 in words is "two hundred fifty-six million, eight hundred twenty thousand, eight hundred eighteen".