256542 has 48 divisors (see below), whose sum is σ = 632448. Its totient is φ = 68640.

The previous prime is 256541. The next prime is 256561. The reversal of 256542 is 245652.

It is a d-powerful number, because it can be written as 2¹⁶ + 5⁴ + 5⁷ + 6⁶ + 4³ + 2¹⁶ .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256542.

It is not an unprimeable number, because it can be changed into a prime (256541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11143 + ... + 11165.

It is an arithmetic number, because the mean of its divisors is an integer number (13176).

2²⁵⁶⁵⁴² is an apocalyptic number.

256542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a pronic number, being equal to 506×507.

It is a practical number, because each smaller number is the sum of distinct divisors of 256542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (316224).

256542 is an abundant number, since it is smaller than the sum of its proper divisors (375906).

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

256542 is a wasteful number, since it uses less digits than its factorization.

256542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 52 counting only the distinct ones).

The product of its digits is 2400, while the sum is 24.

The square root of 256542 is about 506.4997532082. The cubic root of 256542 is about 63.5408215003.

The spelling of 256542 in words is "two hundred fifty-six thousand, five hundred forty-two".