689220009 has 15 divisors (see below), whose sum is σ = 1029928647. Its totient is φ = 459322488.

The previous prime is 689219987. The next prime is 689220019. The reversal of 689220009 is 900022986.

The square root of 689220009 is 26253.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 688275225 + 944784 = 26235^2 + 972^2 .

It is not a de Polignac number, because 689220009 - 2¹⁵ = 689187241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (689220019) by changing a digit.

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 14 ways as a sum of consecutive naturals, for example, 234819 + ... + 237735.

Almost surely, 2^689220009 is an apocalyptic number.

689220009 is the 26253-rd square number.

689220009 is the 13127-th centered octagonal number.

It is an amenable number.

689220009 is a deficient number, since it is larger than the sum of its proper divisors (340708638).

689220009 is an frugal number, since it uses more digits than its factorization.

689220009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5846 (or 2920 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The cubic root of 689220009 is about 883.3224988664.

Multiplying 689220009 by its sum of digits (36), we get a square (24811920324 = 157518²).

The spelling of 689220009 in words is "six hundred eighty-nine million, two hundred twenty thousand, nine".