12720689 has 8 divisors (see below), whose sum is σ = 13015080. Its totient is φ = 12428416.

The previous prime is 12720649. The next prime is 12720707. The reversal of 12720689 is 98602721.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 47089 + 12673600 = 217^2 + 3560^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12720689 - 2¹² = 12716593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12720649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20309 + ... + 20925.

It is an arithmetic number, because the mean of its divisors is an integer number (1626885).

Almost surely, 2^12720689 is an apocalyptic number.

It is an amenable number.

12720689 is a deficient number, since it is larger than the sum of its proper divisors (294391).

12720689 is an equidigital number, since it uses as much as digits as its factorization.

12720689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 12720689 is about 3566.6074917209. The cubic root of 12720689 is about 233.4372786309.

The spelling of 12720689 in words is "twelve million, seven hundred twenty thousand, six hundred eighty-nine".