256567505 has 4 divisors (see below), whose sum is σ = 307881012. Its totient is φ = 205254000.

The previous prime is 256567499. The next prime is 256567547. The reversal of 256567505 is 505765652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 150209536 + 106357969 = 12256^2 + 10313^2 .

It is not a de Polignac number, because 256567505 - 2¹⁴ = 256551121 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25656746 + ... + 25656755.

It is an arithmetic number, because the mean of its divisors is an integer number (76970253).

Almost surely, 2^256567505 is an apocalyptic number.

It is an amenable number.

256567505 is a deficient number, since it is larger than the sum of its proper divisors (51313507).

256567505 is an equidigital number, since it uses as much as digits as its factorization.

256567505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51313506.

The product of its (nonzero) digits is 315000, while the sum is 41.

The square root of 256567505 is about 16017.7247135790. The cubic root of 256567505 is about 635.4292713986.

The spelling of 256567505 in words is "two hundred fifty-six million, five hundred sixty-seven thousand, five hundred five".