16688725 has 6 divisors (see below), whose sum is σ = 20694050. Its totient is φ = 13350960.

The previous prime is 16688723. The next prime is 16688729. The reversal of 16688725 is 52788661.

It can be written as a sum of positive squares in 3 ways, for example, as 4008004 + 12680721 = 2002^2 + 3561^2 .

It is not a de Polignac number, because 16688725 - 2¹ = 16688723 is a prime.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16688723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 333750 + ... + 333799.

Almost surely, 2^16688725 is an apocalyptic number.

It is an amenable number.

16688725 is a deficient number, since it is larger than the sum of its proper divisors (4005325).

16688725 is an equidigital number, since it uses as much as digits as its factorization.

16688725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667559 (or 667554 counting only the distinct ones).

The product of its digits is 161280, while the sum is 43.

The square root of 16688725 is about 4085.1835944055. The cubic root of 16688725 is about 255.5491178453.

The spelling of 16688725 in words is "sixteen million, six hundred eighty-eight thousand, seven hundred twenty-five".