256749408 has 36 divisors (see below), whose sum is σ = 730131948. Its totient is φ = 85583040.

The previous prime is 256749407. The next prime is 256749433. The reversal of 256749408 is 804947652.

It is a happy number.

256749408 is a `hidden beast` number, since 2 + 567 + 49 + 40 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256749407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 445458 + ... + 446033.

It is an arithmetic number, because the mean of its divisors is an integer number (20281443).

Almost surely, 2^256749408 is an apocalyptic number.

It is an amenable number.

256749408 is an abundant number, since it is smaller than the sum of its proper divisors (473382540).

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

256749408 is a wasteful number, since it uses less digits than its factorization.

256749408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891507 (or 891496 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The square root of 256749408 is about 16023.4018859916. The cubic root of 256749408 is about 635.5794062660.

The spelling of 256749408 in words is "two hundred fifty-six million, seven hundred forty-nine thousand, four hundred eight".