256321338 has 64 divisors (see below), whose sum is σ = 658409472. Its totient is φ = 64658880.

The previous prime is 256321337. The next prime is 256321357. The reversal of 256321338 is 833123652.

It is a super-2 number, since 2×256321338² = 131401256628220488, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256321299 and 256321308.

It is not an unprimeable number, because it can be changed into a prime (256321337) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2353 + ... + 22763.

It is an arithmetic number, because the mean of its divisors is an integer number (10287648).

Almost surely, 2^256321338 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256321338, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329204736).

256321338 is an abundant number, since it is smaller than the sum of its proper divisors (402088134).

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

256321338 is a wasteful number, since it uses less digits than its factorization.

256321338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20459.

The product of its digits is 25920, while the sum is 33.

The square root of 256321338 is about 16010.0386632887. The cubic root of 256321338 is about 635.2259827669.

The spelling of 256321338 in words is "two hundred fifty-six million, three hundred twenty-one thousand, three hundred thirty-eight".