1255840565 has 32 divisors (see below), whose sum is σ = 1772430336. Its totient is φ = 836409600.

The previous prime is 1255840559. The next prime is 1255840567. The reversal of 1255840565 is 5650485521.

It is not a de Polignac number, because 1255840565 - 2¹⁴ = 1255824181 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 (1255840567) 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 31 ways as a sum of consecutive naturals, for example, 184004 + ... + 190706.

It is an arithmetic number, because the mean of its divisors is an integer number (55388448).

Almost surely, 2^1255840565 is an apocalyptic number.

It is an amenable number.

1255840565 is a deficient number, since it is larger than the sum of its proper divisors (516589771).

1255840565 is a wasteful number, since it uses less digits than its factorization.

1255840565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6869.

The product of its (nonzero) digits is 240000, while the sum is 41.

The square root of 1255840565 is about 35437.8408625582. The cubic root of 1255840565 is about 1078.8924874904.

The spelling of 1255840565 in words is "one billion, two hundred fifty-five million, eight hundred forty thousand, five hundred sixty-five".