689407778 has 16 divisors (see below), whose sum is σ = 1079595000. Its totient is φ = 329761152.

The previous prime is 689407759. The next prime is 689407801. The reversal of 689407778 is 877704986.

It can be written as a sum of positive squares in 4 ways, for example, as 426546409 + 262861369 = 20653^2 + 16213^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48203 + ... + 60846.

Almost surely, 2^689407778 is an apocalyptic number.

689407778 is a deficient number, since it is larger than the sum of its proper divisors (390187222).

689407778 is a wasteful number, since it uses less digits than its factorization.

689407778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109189.

The product of its (nonzero) digits is 4741632, while the sum is 56.

The square root of 689407778 is about 26256.5759001436. The cubic root of 689407778 is about 883.4027081465.

The spelling of 689407778 in words is "six hundred eighty-nine million, four hundred seven thousand, seven hundred seventy-eight".