256397400 has 720 divisors, whose sum is σ = 1154557800. Its totient is φ = 52254720.

The previous prime is 256397377. The next prime is 256397431. The reversal of 256397400 is 4793652.

256397400 is a `hidden beast` number, since 2 + 563 + 97 + 4 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 13494591 + ... + 13494609.

Almost surely, 2^256397400 is an apocalyptic number.

256397400 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 256397400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (577278900).

256397400 is an abundant number, since it is smaller than the sum of its proper divisors (898160400).

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

256397400 is a wasteful number, since it uses less digits than its factorization.

256397400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 256397400 is about 16012.4139341949. The cubic root of 256397400 is about 635.2888098685.

The spelling of 256397400 in words is "two hundred fifty-six million, three hundred ninety-seven thousand, four hundred".