256408 has 8 divisors (see below), whose sum is σ = 480780. Its totient is φ = 128200.

The previous prime is 256393. The next prime is 256423. The reversal of 256408 is 804652.

It is an interprime number because it is at equal distance from previous prime (256393) and next prime (256423).

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

256408 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16018 + ... + 16033.

2²⁵⁶⁴⁰⁸ is an apocalyptic number.

It is an amenable number.

256408 is a deficient number, since it is larger than the sum of its proper divisors (224372).

256408 is a wasteful number, since it uses less digits than its factorization.

256408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32057 (or 32053 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 256408 is about 506.3674555103. The cubic root of 256408 is about 63.5297564467.

It can be divided in two parts, 25640 and 8, that multiplied together give a triangular number (205120 = T₆₄₀).

The spelling of 256408 in words is "two hundred fifty-six thousand, four hundred eight".