256217400 has 144 divisors (see below), whose sum is σ = 867578400. Its totient is φ = 67760640.

The previous prime is 256217369. The next prime is 256217417. The reversal of 256217400 is 4712652.

256217400 is a `hidden beast` number, since 256 + 2 + 1 + 7 + 400 = 666.

256217400 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 246081 + ... + 247119.

It is an arithmetic number, because the mean of its divisors is an integer number (6024850).

Almost surely, 2^256217400 is an apocalyptic number.

256217400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256217400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (433789200).

256217400 is an abundant number, since it is smaller than the sum of its proper divisors (611361000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256217400 is a wasteful number, since it uses less digits than its factorization.

256217400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198 (or 1186 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 256217400 is about 16006.7923082671. The cubic root of 256217400 is about 635.1401100300.

The spelling of 256217400 in words is "two hundred fifty-six million, two hundred seventeen thousand, four hundred".