256417440 has 48 divisors (see below), whose sum is σ = 807716448. Its totient is φ = 68377856.

The previous prime is 256417439. The next prime is 256417457. The reversal of 256417440 is 44714652.

It is a tau number, because it is divible by the number of its divisors (48).

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 7 ways as a sum of consecutive naturals, for example, 266622 + ... + 267581.

It is an arithmetic number, because the mean of its divisors is an integer number (16827426).

Almost surely, 2^256417440 is an apocalyptic number.

256417440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256417440 is an abundant number, since it is smaller than the sum of its proper divisors (551299008).

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

256417440 is a wasteful number, since it uses less digits than its factorization.

256417440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534221 (or 534213 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 33.

The square root of 256417440 is about 16013.0396864555. The cubic root of 256417440 is about 635.3053608113.

The spelling of 256417440 in words is "two hundred fifty-six million, four hundred seventeen thousand, four hundred forty".