256423565 has 8 divisors (see below), whose sum is σ = 312753048. Its totient is φ = 201775680.

The previous prime is 256423561. The next prime is 256423567. The reversal of 256423565 is 565324652.

It can be written as a sum of positive squares in 4 ways, for example, as 7396 + 256416169 = 86^2 + 16013^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256423565 - 2² = 256423561 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256423561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 420062 + ... + 420671.

It is an arithmetic number, because the mean of its divisors is an integer number (39094131).

Almost surely, 2^256423565 is an apocalyptic number.

It is an amenable number.

256423565 is a deficient number, since it is larger than the sum of its proper divisors (56329483).

256423565 is an equidigital number, since it uses as much as digits as its factorization.

256423565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840799.

The product of its digits is 216000, while the sum is 38.

The square root of 256423565 is about 16013.2309356981. The cubic root of 256423565 is about 635.3104192482.

The spelling of 256423565 in words is "two hundred fifty-six million, four hundred twenty-three thousand, five hundred sixty-five".