689946857 has 4 divisors (see below), whose sum is σ = 696778116. Its totient is φ = 683115600.

The previous prime is 689946821. The next prime is 689946863. The reversal of 689946857 is 758649986.

689946857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 554084521 + 135862336 = 23539^2 + 11656^2 .

It is a cyclic number.

It is not a de Polignac number, because 689946857 - 2¹² = 689942761 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 689946857.

It is not an unprimeable number, because it can be changed into a prime (689946457) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3415478 + ... + 3415679.

It is an arithmetic number, because the mean of its divisors is an integer number (174194529).

Almost surely, 2^689946857 is an apocalyptic number.

It is an amenable number.

689946857 is a deficient number, since it is larger than the sum of its proper divisors (6831259).

689946857 is a wasteful number, since it uses less digits than its factorization.

689946857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6831258.

The product of its digits is 26127360, while the sum is 62.

The square root of 689946857 is about 26266.8394939323. The cubic root of 689946857 is about 883.6329056149.

The spelling of 689946857 in words is "six hundred eighty-nine million, nine hundred forty-six thousand, eight hundred fifty-seven".