256605083505 has 12 divisors (see below), whose sum is σ = 444782144820. Its totient is φ = 136856044512.

The previous prime is 256605083387. The next prime is 256605083513. The reversal of 256605083505 is 505380506652.

256605083505 is a `hidden beast` number, since 2 + 5 + 6 + 60 + 5 + 0 + 83 + 505 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 119317048929 + 137288034576 = 345423^2 + 370524^2 .

It is not a de Polignac number, because 256605083505 - 2³¹ = 254457599857 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 5702335189 = 256605083505 / (2 + 5 + 6 + 6 + 0 + 5 + 0 + 8 + 3 + 5 + 0 + 5).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2851167550 + ... + 2851167639.

It is an arithmetic number, because the mean of its divisors is an integer number (37065178735).

Almost surely, 2^256605083505 is an apocalyptic number.

It is an amenable number.

256605083505 is a deficient number, since it is larger than the sum of its proper divisors (188177061315).

256605083505 is a wasteful number, since it uses less digits than its factorization.

256605083505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5702335200 (or 5702335197 counting only the distinct ones).

The product of its (nonzero) digits is 1080000, while the sum is 45.

The spelling of 256605083505 in words is "two hundred fifty-six billion, six hundred five million, eighty-three thousand, five hundred five".