687726510365 has 4 divisors (see below), whose sum is σ = 825271812444. Its totient is φ = 550181208288.

The previous prime is 687726510323. The next prime is 687726510431. The reversal of 687726510365 is 563015627786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 563015627786 = 2 ⋅281507813893.

It can be written as a sum of positive squares in 2 ways, for example, as 359925603844 + 327800906521 = 599938^2 + 572539^2 .

It is a cyclic number.

It is not a de Polignac number, because 687726510365 - 2³⁴ = 670546641181 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 687726510365.

It is a congruent 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, 68772651032 + ... + 68772651041.

It is an arithmetic number, because the mean of its divisors is an integer number (206317953111).

Almost surely, 2^687726510365 is an apocalyptic number.

It is an amenable number.

687726510365 is a deficient number, since it is larger than the sum of its proper divisors (137545302079).

687726510365 is a wasteful number, since it uses less digits than its factorization.

687726510365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137545302078.

The product of its (nonzero) digits is 12700800, while the sum is 56.

The spelling of 687726510365 in words is "six hundred eighty-seven billion, seven hundred twenty-six million, five hundred ten thousand, three hundred sixty-five".