256474240 has 128 divisors (see below), whose sum is σ = 708549120. Its totient is φ = 87736320.

The previous prime is 256474213. The next prime is 256474241. The reversal of 256474240 is 42474652.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 256474196 and 256474205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256474241) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 118609 + ... + 120751.

It is an arithmetic number, because the mean of its divisors is an integer number (5535540).

Almost surely, 2^256474240 is an apocalyptic number.

256474240 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 256474240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354274560).

256474240 is an abundant number, since it is smaller than the sum of its proper divisors (452074880).

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

256474240 is a wasteful number, since it uses less digits than its factorization.

256474240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2190 (or 2178 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 34.

The square root of 256474240 is about 16014.8131428375. The cubic root of 256474240 is about 635.3522669816.

The spelling of 256474240 in words is "two hundred fifty-six million, four hundred seventy-four thousand, two hundred forty".