689732509 has 4 divisors (see below), whose sum is σ = 726034240. Its totient is φ = 653430780.

The previous prime is 689732507. The next prime is 689732581. The reversal of 689732509 is 905237986.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 689732509 - 2¹ = 689732507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689732501) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 18150837 + ... + 18150874.

It is an arithmetic number, because the mean of its divisors is an integer number (181508560).

Almost surely, 2^689732509 is an apocalyptic number.

It is an amenable number.

689732509 is a deficient number, since it is larger than the sum of its proper divisors (36301731).

689732509 is a wasteful number, since it uses less digits than its factorization.

689732509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36301730.

The product of its (nonzero) digits is 816480, while the sum is 49.

The square root of 689732509 is about 26262.7589754009. The cubic root of 689732509 is about 883.5413891153.

The spelling of 689732509 in words is "six hundred eighty-nine million, seven hundred thirty-two thousand, five hundred nine".