256405536 has 72 divisors (see below), whose sum is σ = 732264624. Its totient is φ = 85104000.

The previous prime is 256405519. The next prime is 256405571. The reversal of 256405536 is 635504652.

It is a happy number.

256405536 is a `hidden beast` number, since 2 + 5 + 640 + 5 + 5 + 3 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a self number, because there is not a number n which added to its sum of digits gives 256405536.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70515 + ... + 74061.

It is an arithmetic number, because the mean of its divisors is an integer number (10170342).

Almost surely, 2^256405536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256405536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (366132312).

256405536 is an abundant number, since it is smaller than the sum of its proper divisors (475859088).

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

256405536 is a wasteful number, since it uses less digits than its factorization.

256405536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3814 (or 3803 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

The square root of 256405536 is about 16012.6679850673. The cubic root of 256405536 is about 635.2955294570.

The spelling of 256405536 in words is "two hundred fifty-six million, four hundred five thousand, five hundred thirty-six".