689565820801 has 27 divisors (see below), whose sum is σ = 820882840323. Its totient is φ = 578556984720.

The previous prime is 689565820793. The next prime is 689565820807. The reversal of 689565820801 is 108028565986.

The square root of 689565820801 is 830401.

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., 102006778225 + 587559042576 = 319385^2 + 766524^2 .

It is not a de Polignac number, because 689565820801 - 2³ = 689565820793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (689565820807) 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 26 ways as a sum of consecutive naturals, for example, 118744440 + ... + 118750246.

Almost surely, 2^689565820801 is an apocalyptic number.

689565820801 is the 830401-st square number.

689565820801 is the 415201-st centered octagonal number.

It is an amenable number.

689565820801 is a deficient number, since it is larger than the sum of its proper divisors (131317019522).

689565820801 is an frugal number, since it uses more digits than its factorization.

689565820801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11662 (or 5831 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 58.

The spelling of 689565820801 in words is "six hundred eighty-nine billion, five hundred sixty-five million, eight hundred twenty thousand, eight hundred one".