687777409 has 8 divisors (see below), whose sum is σ = 789792480. Its totient is φ = 592344000.

The previous prime is 687777403. The next prime is 687777413. The reversal of 687777409 is 904777786.

687777409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 687777409 - 2⁷ = 687777281 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 687777409.

It is not an unprimeable number, because it can be changed into a prime (687777403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1645192 + ... + 1645609.

It is an arithmetic number, because the mean of its divisors is an integer number (98724060).

Almost surely, 2^687777409 is an apocalyptic number.

It is an amenable number.

687777409 is a deficient number, since it is larger than the sum of its proper divisors (102015071).

687777409 is a wasteful number, since it uses less digits than its factorization.

687777409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3290831.

The product of its (nonzero) digits is 4148928, while the sum is 55.

The square root of 687777409 is about 26225.5106527976. The cubic root of 687777409 is about 882.7057770081.

The spelling of 687777409 in words is "six hundred eighty-seven million, seven hundred seventy-seven thousand, four hundred nine".