256436442 has 48 divisors (see below), whose sum is σ = 577886400. Its totient is φ = 85227552.

The previous prime is 256436441. The next prime is 256436447. The reversal of 256436442 is 244634652.

256436442 is a `hidden beast` number, since 2 + 5 + 6 + 4 + 3 + 644 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 256436397 and 256436406.

It is not an unprimeable number, because it can be changed into a prime (256436441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 243934 + ... + 244982.

It is an arithmetic number, because the mean of its divisors is an integer number (12039300).

Almost surely, 2^256436442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256436442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (288943200).

256436442 is an abundant number, since it is smaller than the sum of its proper divisors (321449958).

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

256436442 is a wasteful number, since it uses less digits than its factorization.

256436442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1569 (or 1557 counting only the distinct ones).

The product of its digits is 138240, while the sum is 36.

The square root of 256436442 is about 16013.6330044122. The cubic root of 256436442 is about 635.3210536782.

The spelling of 256436442 in words is "two hundred fifty-six million, four hundred thirty-six thousand, four hundred forty-two".