689535081 has 9 divisors (see below), whose sum is σ = 996108919. Its totient is φ = 459637536.

The previous prime is 689535053. The next prime is 689535083. The reversal of 689535081 is 180535986.

The square root of 689535081 is 26259.

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., 601475625 + 88059456 = 24525^2 + 9384^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 689535081 - 2²¹ = 687437929 is a prime.

It is a super-2 number, since 2×689535081² = 950917255859353122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689535083) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 74401 + ... + 83153.

Almost surely, 2^689535081 is an apocalyptic number.

689535081 is the 26259-th square number.

689535081 is the 13130-th centered octagonal number.

It is an amenable number.

689535081 is a deficient number, since it is larger than the sum of its proper divisors (306573838).

689535081 is an frugal number, since it uses more digits than its factorization.

689535081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17512 (or 8756 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The cubic root of 689535081 is about 883.4570798827.

The spelling of 689535081 in words is "six hundred eighty-nine million, five hundred thirty-five thousand, eighty-one".