256018381 has 4 divisors (see below), whose sum is σ = 259259200. Its totient is φ = 252777564.

The previous prime is 256018349. The next prime is 256018387. The reversal of 256018381 is 183810652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 256018381 - 2⁵ = 256018349 is a prime.

It is a super-3 number, since 3×256018381³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256018387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1620291 + ... + 1620448.

It is an arithmetic number, because the mean of its divisors is an integer number (64814800).

Almost surely, 2^256018381 is an apocalyptic number.

It is an amenable number.

256018381 is a deficient number, since it is larger than the sum of its proper divisors (3240819).

256018381 is an equidigital number, since it uses as much as digits as its factorization.

256018381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3240818.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 256018381 is about 16000.5743959397. The cubic root of 256018381 is about 634.9756173083.

The spelling of 256018381 in words is "two hundred fifty-six million, eighteen thousand, three hundred eighty-one".