256423135565 has 8 divisors (see below), whose sum is σ = 314254736640. Its totient is φ = 200773859152.

The previous prime is 256423135561. The next prime is 256423135571. The reversal of 256423135565 is 565531324652.

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

It is a cyclic number.

It is not a de Polignac number, because 256423135565 - 2² = 256423135561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256423135561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 545580905 + ... + 545581374.

It is an arithmetic number, because the mean of its divisors is an integer number (39281842080).

Almost surely, 2^256423135565 is an apocalyptic number.

It is an amenable number.

256423135565 is a deficient number, since it is larger than the sum of its proper divisors (57831601075).

256423135565 is a wasteful number, since it uses less digits than its factorization.

256423135565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1091162331.

The product of its digits is 3240000, while the sum is 47.

The spelling of 256423135565 in words is "two hundred fifty-six billion, four hundred twenty-three million, one hundred thirty-five thousand, five hundred sixty-five".