681375565 has 8 divisors (see below), whose sum is σ = 880546968. Its totient is φ = 503169600.

The previous prime is 681375557. The next prime is 681375577. The reversal of 681375565 is 565573186.

It can be written as a sum of positive squares in 4 ways, for example, as 120538441 + 560837124 = 10979^2 + 23682^2 .

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

It is not a de Polignac number, because 681375565 - 2³ = 681375557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 5241286 + ... + 5241415.

It is an arithmetic number, because the mean of its divisors is an integer number (110068371).

Almost surely, 2^681375565 is an apocalyptic number.

681375565 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

681375565 is a deficient number, since it is larger than the sum of its proper divisors (199171403).

681375565 is a wasteful number, since it uses less digits than its factorization.

681375565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10482719.

The product of its digits is 756000, while the sum is 46.

The square root of 681375565 is about 26103.1715505990. The cubic root of 681375565 is about 879.9584884861.

The spelling of 681375565 in words is "six hundred eighty-one million, three hundred seventy-five thousand, five hundred sixty-five".